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                                                                   EXHIBIT 10.20


                             WEBLINK WIRELESS, INC.

                FIFTH AMENDED AND RESTATED 1991 STOCK OPTION PLAN


                                    ARTICLE I

                               GENERAL PROVISIONS


         1. PURPOSE

         The purpose of the WebLink Wireless, Inc. Fifth Amended and Restated
1991 Stock Option Plan (the "Plan") is to strengthen WebLink Wireless, Inc., a
Delaware corporation (the "Corporation"), by providing eligible individuals who
are responsible for the management, growth and financial success of the
Corporation or who otherwise render valuable services to the Corporation with
the opportunity to acquire a proprietary interest, or increase their proprietary
interest, in the Corporation and thereby providing a means of attracting
competent personnel and encouraging them to remain in the service of the
Corporation.

         2. ADMINISTRATION OF THIS PLAN

         This Plan shall be administered by the Stock Option Committee of the
Board (the "Committee") which shall be comprised of two (2) or more directors,
each of whom shall be a "non-employee director," as defined in Rule 16b-3,
promulgated under the Securities Exchange Act of 1934, as amended (the "Exchange
Act"). The Committee shall have full power and authority (subject to the
provisions of this Plan) to establish such rules and regulations as it may deem
appropriate for the proper Plan administration and to construe the terms of and
make such determinations under, and issue such interpretations of, this Plan and
any outstanding option grants as it may deem necessary or advisable. Decisions
of the Committee shall be final and binding on all parties who have an interest
in this Plan or any outstanding option.

         3. PERSONS ELIGIBLE TO RECEIVE OPTION GRANTS

                  (a) The persons eligible to receive option grants pursuant to
         this Plan ("Optionees") are limited to key employees (including
         officers and directors) of the Corporation (or its Parent or Subsidiary
         (as such terms are hereinafter defined) corporations) who render
         services which contribute to the success and growth of the Corporation
         (or its Parent or Subsidiary corporations) or which may reasonably be
         anticipated to contribute to the future success and growth of the
         Corporation (or its Parent or Subsidiary corporations).

                  (b) The Committee shall have full authority to determine, with
         respect to the option grants made under this Plan, which eligible
         individuals are to receive option grants, the number of shares to be
         covered by each such grant, the status of the granted option as either
         an Incentive Option or a Non-Statutory Option (as such terms are
         hereinafter defined), the time or times at which each granted option is
         to become exercisable and the maximum term for which the option may
         remain outstanding.



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         4. STOCK SUBJECT TO THIS PLAN

                  (a) The stock issuable under this Plan shall be shares of the
         Corporation's authorized but unissued or reacquired Class A convertible
         common stock, par value $.0001 per share ("Common Stock"). The maximum
         number of shares which may be issued over the term of this Plan shall
         not exceed 9,500,000 shares. However, any shares of Common Stock issued
         under the Corporation's Third Amended and Restated 1991 Stock Issuance
         Plan will reduce, on a share-for-share basis, the number of shares
         issuable under this Plan. The total number of shares issuable in the
         aggregate under this Plan and the Third Amended and Restated 1991 Stock
         Issuance Plan shall be subject to adjustment from time to time in
         accordance with the provisions of Section 4(c) of this Article I.

                  (b) Shares subject to (i) the portion of one or more
         outstanding options which are not exercised prior to expiration or
         termination and (ii) outstanding options cancelled in accordance with
         the cancellation-regrant provisions of Section 5 of Article II will be
         available for subsequent option grants under this Plan. The shares
         which shall not be available for subsequent option grants under this
         Plan include (A) shares subject to an option surrendered under this
         Plan in connection with a Change in Control (as such term is
         hereinafter defined) and (B) shares issued pursuant to the exercise of
         an option (whether as vested or unvested shares) which are repurchased
         by the Corporation.

                  (c) In the event that the Committee shall determine that any
         dividend or other distribution (whether in the form of shares of Common
         Stock or other securities), recapitalization, stock split, reverse
         stock split, reorganization, merger, consolidation, split-up, spin-off,
         combination, repurchase or exchange of securities of the Corporation,
         or other similar corporate transaction or event affects the benefits or
         potential benefits intended to be made available under this Plan such
         that an adjustment is determined by the Committee to be appropriate in
         order to prevent dilution or enlargement of the benefits or potential
         bene fits intended to be made available under this Plan, then the
         Committee may, in such manner as it may deem equitable, adjust any or
         all of (i) the number of shares of Common Stock subject to this Plan
         and which thereafter may be made the subject of options under this
         Plan, (ii) the number of shares of Common Stock subject to outstanding
         options, (iii) the nature of the consideration (including, without
         limitation, other securities of the Corporation, securities of another
         entity and/or other property) to be received upon exercise of an option
         and/or (iv) the grant, purchase or exercise price with respect to any
         option, or, if deemed appropriate, make provisions for a cash payment
         to the holder of an outstanding option; provided, however, in each
         case, that with respect to Incentive Options no such adjustment shall
         be authorized to the extent that such adjustment would cause this Plan
         to violate Section 422(b)(1) or 424(a) of the Code (as such term is
         hereinafter defined) or any successor provisions thereto; and provided
         further, however, that the number of shares of Common Stock subject to
         any option payable or denominated in shares of Common Stock shall
         always be a whole number. Notwithstanding the foregoing, Non-Statutory
         Options shall be subject to only such adjustment as shall be necessary
         to maintain the proportionate interest of the Optionee and preserve,
         without exceeding, the value of such option.



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                  (d) Common Stock issuable under this Plan may be subject to
         such restrictions as may be determined by the Committee, including,
         without limitation, restrictions on transfer, repurchase rights and
         other restrictions.

         5. DEFINITIONS

                  The following definitional provisions shall be in effect for
         all purposes under this Plan:

                  (a) Board means the board of directors of WebLink Wireless,
         Inc.

                  (b) Change in Control means the acquisition of fifty percent
         (50%) or more of the Corporation's outstanding voting stock pursuant to
         a tender or exchange offer made by a person or group of related persons
         (other than the Corporation or a person that directly or indirectly
         controls, is controlled by or is under common control with the
         Corporation) which the Board does not recommend to the stockholders.

                  (c) Code means the Internal Revenue Code of 1986, as amended.

                  (d) Corporation means WebLink Wireless, Inc., a Delaware
         corporation.

                  (e) Corporate Transaction means one or more of the following
         stockholder-approved transactions:

                           (i) a merger or consolidation in which the
                  Corporation is not the surviving entity, provided securities
                  possessing fifty percent (50%) or more of the total combined
                  voting power of the Corporation's outstanding voting
                  securities are transferred to a person or persons different
                  from those who held such securities immediately prior to such
                  transaction,

                           (ii) the sale, transfer or other disposition of all
                  or substantially all of the assets of the Corporation other
                  than in the ordinary course of business, or

                           (iii) any reverse merger in which the Corporation is
                  the surviving entity but in which securities possessing fifty
                  percent (50%) or more of the total combined voting power of
                  the Corporation's outstanding voting securities are
                  transferred to person or persons different from those who held
                  such securities immediately prior to such merger.

         In no event shall any merger, consolidation or other reorganization
         involving the Corporation be deemed to constitute a Corporate
         Transaction if the primary purpose of such transaction is either to
         change the State in which the Corporation is incorporated or to create
         a holding-company structure whereby the Corporation's stockholders of
         record become the stockholders of the holding company.



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                  (f) Employee means an individual who is in the employ of the
         Corporation or one or more Parent or Subsidiary corporations. An
         Optionee shall be considered to be an Employee for so long as such
         individual remains in the employ of the Corporation or one or more
         Parent or Subsidiary corporations, subject to the control and direction
         of the employer entity as to both the work to be performed and the
         manner and method of performance.

                  (g) Exercise Date shall be the date on which both (i) written
         notice of the exercise of an outstanding option under this Plan and
         (ii) payment of the option price are delivered to the Corporation.

                  (h) Fair Market Value of a share of Common Stock on any
         relevant date shall be determined in accordance with the following
         provisions:

                           (i) If the Common Stock is not at the time listed or
                  admitted to trading on any national securities exchange but is
                  traded in the over-the-counter market, the Fair Market Value
                  shall be the mean between the highest bid and the lowest asked
                  prices (or, if such information is available, the closing
                  sales price) per share of Common Stock on the date in question
                  in the over-the-counter market, as such prices are reported by
                  the National Association of Securities Dealers through its
                  Nasdaq National Market System or any successor system. If
                  there are no reported bid and asked prices (or closing sales
                  price) for the Common Stock on the date in question, then the
                  mean between the highest bid and lowest asked prices (or
                  closing sales price) on the last preceding date for which such
                  quotations exist shall be determinative of Fair Market Value.

                           (ii) If the Common Stock is at the time listed or
                  admitted to trading on any national securities exchange, then
                  the Fair Market Value shall be the closing sales price per
                  share of Common Stock on the date in question on the national
                  securities exchange determined by the Committee to be the
                  primary market for the Common Stock, as such price is
                  officially quoted in the composite tape of transactions on
                  such exchange. If there is no reported sale of Common Stock on
                  such exchange on the date in question, then the fair market
                  value shall be the closing sales price on the exchange on the
                  last preceding date for which such quotation exists.

                           (iii) If the Common Stock is at the time neither
                  listed nor admitted to trading on any national securities
                  exchange nor traded in the over-the-counter market, or if the
                  Committee determines that the valuation provisions of
                  subparagraphs (i) and (ii) above will not result in a true and
                  accurate valuation of the Common Stock, then the Fair Market
                  Value shall be determined by the Committee after taking into
                  account such factors as the Committee shall deem appropriate
                  under the circumstances.

                  (i) Incentive Option means an incentive stock option which
         satisfies the requirements of Section 422 of the Code.



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                  (j) Non-Statutory Option means an option that does not meet
         (whether at the time of the grant of such option or subsequently) the
         statutory requirements prescribed for an Incentive Option.

                  (k) Notice of Grant means written notification (in
         substantially the form attached hereto as EXHIBIT B) of the grant of an
         option pursuant to this Plan.

                  (l) Parent corporation means any corporation which, directly
         or indirectly, owns, at the time of the determination, stock possessing
         fifty percent (50%) or more of the total combined voting power of all
         classes of stock of the Corporation.

                  (m) Permanent Disability shall have the meaning set forth in
         Section 22(e)(3) of the Code, or any successor provision thereto.

                  (n) Plan means this Fifth Amended and Restated 1991 Stock
         Option Plan of the Corporation.

                  (o) Service means the performance of services for the
         Corporation or one or more Parent or Subsidiary corporations by an
         individual in the capacity of an Employee or a non- employee member of
         the Board or the board of directors of such Parent or Subsidiary
         corporations, unless a different meaning is specified in the Stock
         Option Agreement. An Optionee shall be deemed to remain in Service for
         so long as such individual renders services to the Corporation or any
         Parent or Subsidiary corporation on a periodic basis in the capacity of
         an Employee or a non-employee member of the Board or the board of
         directors of such Parent or Subsidiary corporation.

                  (p) Stock Option Agreement means a stock option agreement, in
         substantially the form attached hereto as EXHIBIT A and incorporated
         herein by reference (the "Stock Option Agreement"), incorporating any
         repurchase rights or first refusal rights retained by the Corporation
         with respect to the Common Stock purchased under an option.

                  (q) Subsidiary corporation means any corporation of which the
         Corporation, directly or indirectly, owns, at the time of the
         determination, stock possessing fifty percent (50%) or more of the
         total combined voting power of all classes of stock of the corporation
         in question.

                  (r) 10% Stockholder means the owner of stock (as determined
         under Section 424(d) of the Code) possessing 10% or more of the total
         combined voting power and value of all classes of stock of the
         Corporation or any Parent or Subsidiary corporation.



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                                   ARTICLE II

                                  OPTION GRANTS

         1. TERMS AND CONDITIONS OF OPTIONS

         Options granted pursuant to this Plan shall be authorized by action of
the Committee and may, at the discretion of the Committee, be either Incentive
Options or Non-Statutory Options. Each granted option shall be evidenced by a
Stock Option Agreement and a Notice of Grant; provided, however, that each Stock
Option Agreement shall comply with and incorporate the terms and conditions
specified below. Each Stock Option Agreement evidencing an Incentive Option
shall, in addition, be subject to the applicable provisions of Section 2 of this
Article II.

                  (a) Option Price.

                           (i) The option price per share shall be fixed by the
                  Committee; provided, however, that in no event shall the
                  option price per share be less than eighty-five percent (85%)
                  for Non-Statutory Options or less than one hundred percent
                  (100%) for Incentive Options of the Fair Market Value of a
                  share of Common Stock on the date of the option grant.

                           (ii) If the individual to whom the option is granted
                  is at the time a 10% Stockholder and the option granted is an
                  Incentive Option, then the option price per share shall not be
                  less than one hundred ten percent (110%) of the Fair Market
                  Value of the Common Stock on the grant date.

                           (iii) The option price shall be payable in such form
                  and by such method as shall be determined by the Committee,
                  including, without limitation, cash (subject to the provisions
                  of Article III, Section 1), shares of Common Stock, other
                  securities or other property or any combination thereof,
                  having a fair market value (as determined in accordance with
                  the terms of this Plan in the case of Common Stock and in all
                  other cases by such methods or procedures as shall be
                  authorized by the Committee) on the Exercise Date equal to the
                  relevant exercise price (including payment in accordance with
                  a cashless exercise program under which, if so instructed by
                  the person exercising the option, shares of Common Stock may
                  be issued directly to such person's broker or dealer upon
                  receipt of the purchase price in cash from the broker or
                  dealer).

                  (b) Term and Exercise of Options. Each option granted under
         this Plan shall be exercisable at such time or times, during such
         period, and for such number of shares of Common Stock as shall be
         determined by the Committee and set forth in the Stock Option Agreement
         evidencing such option. However, no option granted under this Plan
         shall have


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         a term in excess of ten (10) years from the grant date, and no
         Incentive Option granted to a 10% Stockholder shall have a term in
         excess of five (5) years from the grant date.

                  (c) Nontransferability of Options. During the lifetime of the
         Optionee, the option shall be exercisable only by the Optionee or by
         the Optionee's duly appointed guardian or personal representative and
         shall not be assignable or transferable by the Optionee otherwise than
         by will or by the laws of descent and distribution following the
         Optionee's death.

                  (d) Termination of Service.

                           (i) Should an Optionee cease to remain in Service for
                  any reason other than (i) Permanent Disability, (ii) death or
                  (iii) for Cause (as such term is hereinafter defined), an
                  option (to the extent otherwise exercisable on the date of
                  such termination) shall be exercisable by the Optionee at any
                  time prior to the expiration date of the option (except as
                  otherwise provided pursuant to Section 6 of this Article II)
                  or within three (3) months after the date of such termination,
                  whichever is the shorter period.

                           (ii) If an Optionee's Service ceases by reason of the
                  Optionee's Permanent Disability, an option (to the extent
                  otherwise exercisable on the date of such termination by
                  reason of Permanent Disability) shall remain exercisable by
                  the Optionee at any time prior to the expiration date of the
                  option (except as otherwise provided pursuant to Section 6 of
                  this Article II) or within twelve (12) months after the date
                  of such termination, whichever is the shorter period.

                           (iii) If an Optionee's Service ceases as a result of
                  death, an option (to the extent otherwise exercisable on the
                  date of the death of such Optionee) shall remain exercisable
                  by the person or persons entitled to do so under the
                  Optionee's will, or, if the Optionee shall fail to make
                  testamentary disposition of said option or shall die
                  intestate, by the Optionee's legal representative or
                  representatives, at any time prior to the expiration date of
                  the option (except as otherwise provided pursuant to Section 6
                  of this Article II) or within twelve (12) months after the
                  date of such death, whichever is the shorter period.

                           (iv) If the Optionee's Service ceases as a result of
                  termination for Cause (as hereinafter defined), any then
                  outstanding options of such Optionee shall automatically
                  terminate as of the termination date. As used herein,
                  termination for "Cause" shall mean termination upon the
                  occurrence of one or more of the following events:

                                    (A) The Optionee's failure to substantially
                           perform his duties with the Corporation or any Parent
                           or Subsidiary corporation as determined by the
                           Committee in its sole discretion following receipt by
                           the Optionee of written notice of such failure and
                           the Optionee's failure to remedy such failure within


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                           thirty (30) days after receipt of such notice (other
                           than failure from his incapacity during physical or
                           mental illness);

                                    (B) The Optionee's willful failure or
                           refusal to perform specific directives of the Board,
                           which directives are consistent with the scope and
                           nature of the Optionee's duties and responsibilities,
                           and which are not remedied by the Optionee within
                           thirty (30) days after being notified in writing of
                           his failure by the Board;

                                    (C) The Optionee's conviction of a felony;
                           or

                                    (D) A breach of the Optionee's fiduciary
                           duty to the Corporation or any Parent or Subsidiary
                           corporation or willful violation in the course of
                           performing his duties for the Corporation or any
                           Parent or Subsidiary corporation of any law, rule or
                           regulation (other than traffic violations or other
                           minor offenses). No act or failure to act on the
                           Optionee's part shall be considered willful unless
                           done or omitted to be done in bad faith and without
                           reasonable belief that the action or omission was in
                           the best interest of the Corporation or any Parent or
                           Subsidiary corporation.

                  (e) Stockholder Rights. No shares of Common Stock shall be
         issued until payment, as provided herein, therefor has been made. An
         Optionee shall have none of the rights of a stockholder with respect to
         the Common Stock covered by an option until such Optionee shall have
         exercised the option and paid the option price.

         2. INCENTIVE OPTIONS

         The terms and conditions specified below shall be applicable to all
Incentive Options granted under this Plan. Incentive Options may only be granted
to individuals who are Employees. Options which are specifically designated as
Non-Statutory Options when issued under this Plan shall not be subject to such
terms and conditions.

                  (a) Option Price. The option price per share of the Common
         Stock subject to an Incentive Option shall in no event be less than one
         hundred percent (100%) of the Fair Market Value of a share of Common
         Stock on the grant date.

                  (b) Dollar Limitation. The aggregate Fair Market Value
         (determined as of the respective date or dates of grant) of the Common
         Stock for which one or more options granted to any Employee under this
         Plan (or any other plan of the Corporation or any Parent or Subsidiary
         corporation) may for the first time become exercisable as incentive
         stock options under the Federal tax laws during any one calendar year
         shall not exceed the sum of One Hundred Thousand Dollars ($100,000). To
         the extent the Employee holds two or more such options which become
         exercisable for the first time in the same calendar year, the foregoing
         limitation on the exercisability thereof as Incentive Options under the
         Federal tax


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         laws shall be applied on the basis of the order in which such options
         are granted. In the event the limits of this Section 2(b) would
         otherwise be exceeded, the Optionee may still exercise the options, but
         such option, to the extent of such excess, shall be deemed to be a
         Non-Statutory Option. Except as modified by the preceding provisions of
         this Section 2, all the provisions of this Plan shall be applicable to
         the Incentive Options granted hereunder.

         3. LIMITED SURRENDER RIGHTS

                  (a) Should a Change in Control occur at a time when the
         Corporation's outstanding capital stock is registered under Section 12
         of the Exchange Act, then each Optionee who is at the time an officer
         or director of the Corporation subject to the short-swing profit
         restrictions of the Federal securities laws shall have the right to
         surrender any or all options held by such individual under this Plan,
         to the extent such options have been outstanding for at least six (6)
         months and are at the time exercisable for vested shares. In return for
         each surrendered option, the officer or director shall receive an
         appreciation distribution from the Corporation in an amount equal to
         the excess of (i) the aggregate Acquisition Price (as such term is
         hereinafter defined) of the number of shares in which such individual
         is at the time vested under the surrendered option over (ii) the
         aggregate option price payable for such vested shares. Such limited
         surrender right shall be exercisable for a period not to exceed thirty
         (30) days following the completion of the Change in Control. Neither
         the approval of the Committee nor the consent of the Board shall be
         required for such surrender, and the distribution to which such
         Optionee shall become entitled upon the option surrender shall be made
         entirely in cash.

                  (b) The "Acquisition Price" per share of the vested Common
         Stock subject to the surrendered option shall be deemed to be equal to
         the greater of (i) the Fair Market Value per share on the date of
         surrender or (ii) the highest reported price per share paid in
         effecting the Change in Control of the Corporation's outstanding voting
         stock. However, if the surrendered option is an Incentive Option, then
         the Acquisition Price of the vested shares subject to the surrendered
         option shall not exceed the clause (i) value per share.

         4. CORPORATE TRANSACTIONS

                  (a) In the event of any Corporate Transaction, except as
         otherwise provided in the agreement evidencing the grant of an option
         hereunder, each option outstanding under this Plan shall automatically
         accelerate so that each such option shall, immediately prior to the
         specified effective date for such Corporate Transaction, become fully
         exercisable with respect to the total number of shares of Common Stock
         at the time subject to such option and may be exercised for all or any
         portion of such shares.

                  (b) Upon the consummation of the Corporate Transaction, except
         as otherwise provided in the agreement evidencing the grant of an
         option hereunder, each option outstanding under this Plan shall
         terminate and cease to be exercisable.



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                  (c) The exercisability as incentive stock options under the
         Federal tax laws of any options accelerated in connection with the
         Corporate Transaction shall remain subject to the applicable dollar
         limitation of subsection 2(b) of this Article II.

                  (d) The grant of options under this Plan shall in no way
         affect the legal right of the Corporation to adjust, reclassify,
         reorganize or otherwise change its capital or business structure or to
         merge, consolidate, dissolve, liquidate or sell or transfer all or any
         part of its business or assets.

         5. CANCELLATION AND NEW GRANT OF OPTIONS

         The Committee shall have the authority to effect, at any time and from
time to time, with the consent of the affected Optionees, the cancellation of
any or all outstanding options under this Plan and to grant in substitution
therefor new options under this Plan covering the same or different numbers of
shares of Common Stock but having an option price per share not less than
eighty-five percent (85%) of the Fair Market Value per share of Common Stock on
the new grant date (or one hundred percent (100%) of such Fair Market Value in
the case of an Incentive Option or, in the case of an Incentive Option held by a
10% Stockholder, not less than one hundred and ten percent (110%) of such Fair
Market Value).

         6. EXTENSION OF EXERCISE PERIOD

         The Committee shall have full power and authority to extend (either at
the time while the option is granted or at any time while the option remains
outstanding) the period of time for which the option is to remain exercisable
following an Optionee's cessation of Service, from the limited period set forth
in the Stock Option Agreement to such greater period of time as the Committee
may deem appropriate under the circumstances. In no event, however, shall such
option be exercisable after the specified expiration date of the option term.


                                   ARTICLE III

                                  MISCELLANEOUS

         1. LOANS

                  (a) The Committee may assist any Optionee (including an
         Optionee who is an officer or director of the Corporation) in the
         exercise of one or more options granted to such Optionee under this
         Plan, including the satisfaction of any Federal, State and local income
         and employment tax obligations arising therefrom, by

                           (i) authorizing the extension of a loan from the
                  Corporation to such Optionee, or



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                           (ii) permitting the Optionee to pay the option price
                  for the purchased Common Stock in installments over a period
                  of years.

                  (b) The terms of any loan or installment method of payment
         (including the interest rate and terms of repayment) shall be
         established by the Committee in its sole discretion. Loans or
         installment payments may be granted with or without security or
         collateral. In all events the maximum credit available to each Optionee
         may not exceed the sum of (i) the aggregate option price or purchase
         price payable for the purchased shares (less the par value payable for
         the purchased shares) plus (ii) any Federal, State or local income and
         employment tax liability incurred by the Optionee in connection with
         such exercise.

                  (c) The Committee may, in its absolute discretion, determine
         that one or more loans extended under the financial assistance program
         shall be subject to forgiveness by the Corporation in whole or in part
         upon such terms and conditions as the Committee in its discretion deems
         appropriate.

         2. AMENDMENT OF THIS PLAN AND AWARDS

                  (a) The Board shall have complete and exclusive power and
         authority to amend, modify, suspend, discontinue or terminate this Plan
         in any or all respects whatsoever. However, no such amendment,
         modification, suspension, discontinuance or termination shall adversely
         affect the rights and obligations of an Optionee with respect to
         options at the time outstanding under this Plan, unless the Optionee
         consents thereto. No option may be granted during any suspension of
         this Plan or after its termination. In addition, the Board shall not,
         without the approval of the Corporation's stockholders, amend this Plan
         to (i) materially increase the maximum number of shares issuable under
         this Plan (except for permissible adjustments under Article I, Section
         4(c)), (ii) change the minimum option price, (iii) increase the maximum
         terms for options granted hereunder, (iv) remove the administration of
         this Plan from the Committee, (v) materially increase the benefits
         accruing to individuals who participate in this Plan or (vi) materially
         modify the eligibility requirements for participation in this Plan.

                  (b) Options to purchase shares of Common Stock may be granted
         under this Plan which are in excess of the number of shares then
         available for issuance under this Plan, provided there is obtained
         Board approval of an amendment sufficiently increasing the number of
         shares of Common Stock available for issuance under this Plan prior to
         the actual option grant and stockholder approval of such amendment
         prior to the exercise of the option. If such stockholder approval is
         not obtained within twelve (12) months after the date the amendment to
         this Plan is approved by the Board, then all options representing such
         excess shall terminate and cease to be exercisable.



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         3. EFFECTIVE DATE AND TERM OF PLAN

                  (a) This Plan shall become effective when adopted by the
         Board. All options previously granted under this Plan shall remain in
         full force and effect, subject to the terms of the Stock Option
         Agreements under which they were issued and this Plan.

                  (b) This Plan shall terminate upon the earlier of (i) August
         19, 2001 or (ii) the date on which all shares available for issuance
         under this Plan have been issued or cancelled pursuant to the exercise
         or surrender of options granted hereunder. If the date of termination
         is determined under clause (i) above, then no options outstanding on
         such date shall be affected by the termination of this Plan, and such
         securities shall thereafter continue to have force and effect in
         accordance with the provisions of the Stock Option Agreements
         evidencing such options.

         4. USE OF PROCEEDS

         Any cash proceeds received by the Corporation from the issuance of
shares of Common Stock under this Plan shall be used for general corporate
purposes.

         5. CONTINUATION OF EMPLOYMENT

         Nothing contained in this Plan (or in any option granted pursuant to
this Plan) shall confer upon any Optionee any right to continue in the employ of
the Corporation or any Parent or Subsidiary corporation or constitute any
contract or agreement of employment or interfere in any way with the right of
the Corporation or any Parent or Subsidiary corporation to reduce any Optionee's
compensation from the rate in existence at the time of the granting of an option
or to terminate such Optionee's employment. Nothing contained herein or in any
Stock Option Agreement shall affect any other contractual rights of an Optionee.

         6. WITHHOLDING

         The Corporation's obligation to deliver shares upon the exercise or
surrender of any options granted under this Plan shall be subject to the
satisfaction of all applicable Federal, State and local income and employment
tax withholding requirements. The Corporation or any Parent or Subsidiary
corporation that employs any Optionee shall have the right to deduct any sums
that the Committee reasonably determines that Federal, State or local tax law
requires to be withheld with respect to the exercise of any option or as
otherwise may be required by those laws. Neither the Corporation nor any Parent
or Subsidiary corporation shall be obligated to advise any Optionee of the
existence of the tax or the amount which the employer corporation will be so
required to withhold. Upon the exercise of a Non-Statutory Option, if tax
withholding is required, an Optionee may, with the consent of the Committee,
have shares of Common Stock withheld ("Share Withholding") by the Corporation
from the shares otherwise to be received; provided, however, that if the
Optionee is subject to the provisions of Section 16 under the Exchange Act, no
Share Withholding shall be permitted unless such transaction complies with the
requirements of Rule 16b-3 promulgated under


                                      -12-

<PAGE>   13
the Exchange Act. The number of shares so withheld should have an aggregate Fair
Market Value on the date of exercise sufficient to satisfy the applicable
withholding taxes.

         7. REGULATORY APPROVALS

         The implementation of this Plan, the granting of any options hereunder
and the issuance of Common Stock upon the exercise or surrender of the option
grants made hereunder shall be subject to the Corporation's procurement of all
approvals and permits required by regulatory authorities having jurisdiction
over this Plan, the options granted under it and the Common Stock issued
pursuant to it. Without limiting the generality of the foregoing, no options
granted hereunder may be exercised and no shares of Common Stock issuable upon
exercise of such options may be transferred unless and until the Committee
determines that such exercise/transfer will be made in compliance with all
applicable laws, rules and regulations, including, without limitation,
applicable securities laws, rules and regulations. The Corporation does not have
any obligation to take any action to (i) register or qualify options or shares
of Common Stock pursuant to applicable laws or to perfect an exemption from such
registration/qualification requirements or (ii) list the shares of Common Stock
for trading on any stock exchange or automated transaction reporting system.

         8. GOVERNING LAW

         This Plan and the options issued hereunder shall be governed by, and
construed and enforced in accordance with, the laws of the State of Texas
applicable to contracts made and performed within that State.

         9. COMPLIANCE WITH RULE 16B-3

         At such time and so long as the Corporation shall have a class of
equity securities registered under Section 12 of the Exchange Act, it is
intended that this Plan be applied and administered in compliance with Rule
16b-3. If any provision of this Plan would be in violation of Rule 16b-3 if
applied as written, such provision shall not have effect as written and shall be
given effect so as to comply with Rule 16b-3, as determined by the Committee.
The Board is authorized to amend this Plan and to make any such modifications to
the Stock Option Agreements to comply with Rule 16b-3, as it may be amended from
time to time, and to make any other such amendments or modifications deemed
necessary or appropriate to better accomplish the purposes of this Plan in light
of any amendments made to Rule 16b-3.

         10. NO LIABILITY FOR GOOD FAITH DETERMINATIONS

         Neither the members of the Board nor any member of the Committee shall
be liable for any action, failure to act, omission or determination taken or
made in good faith with respect to this Plan or any option granted under it.



                                      -13-

<PAGE>   14



         11. OTHER BENEFITS

         Participation in this Plan shall not preclude the Optionee from
eligibility in any other stock option plan of the Company or any Parent or
Subsidiary corporation or any old age, benefit, insurance, pension, profit
sharing, retirement, bonus or other extra compensation plans which the
Corporation or any Parent or Subsidiary corporation has adopted, or may, at any
time, adopt for the benefit of its employees.

         12. EXECUTION OF RECEIPTS AND RELEASES

         Any payment or any issuance or transfer of shares of Common Stock to an
Optionee, or to his legal representative, heir, legatee or distributee, in
accordance with the provisions hereof, shall, to the extent thereof, be in full
satisfaction of all claims of such persons hereunder. The Committee may require
any Optionee, legal representative, heir, legatee or distributee, as a condition
precedent to such payment, to execute a release and receipt therefor in such
form as it shall determine.

         13. PAYMENT OF EXPENSES

         All expenses incident to the administration, termination or performance
of this Plan, including, without limitation, legal and accounting fees, shall be
paid by the Corporation. All expenses incurred by an Optionee shall be paid by
such Optionee.

         14. CORPORATE RECORDS

         Records of the Corporation or any Parent or Subsidiary corporation
regarding the Optionee's period of employment, termination of employment and the
reason therefor, leaves of absence, re-employment and other matters shall be
conclusive for all purposes hereunder, unless determined by the Board to be
incorrect.


                                      -14-

<PAGE>   15
                                    EXHIBIT A

                             STOCK OPTION AGREEMENT



<PAGE>   16

                                                                       EXHIBIT A

                             STOCK OPTION AGREEMENT

                                   WITNESSETH:

                                    RECITALS

Section A. The Board of Directors of WebLink Wireless, Inc., a Delaware
corporation (the "Company"), has adopted the WebLink Wireless, Inc. Fifth
Amended and Restated 1991 Stock Option Plan (the "Plan") for the purpose of
attracting and retaining the services of selected key employees (including
officers and directors) and non-employee members of the Board who contribute to
the financial success of the Company.

Section B. Optionee is an individual who is to render valuable services to the
Company, and this Agreement is executed pursuant to, and is intended to carry
out the purposes of, the Plan in connection with the Company's grant of a stock
option to Optionee.

Section C. Capitalized terms used in this Agreement shall, unless the context
clearly indicates otherwise, have the meaning assigned to such terms in
Paragraph 24 of this Agreement.

         NOW, THEREFORE, it is hereby agreed as follows:

1. Grant of Option. Subject to and upon the terms and conditions set forth in
this Agreement, the Company hereby grants to Optionee, as of the Grant Date, a
stock option to purchase up to that number of Option Shares as is specified in
the Grant Notice. The Option Shares shall be purchasable from time to time
during the option term at the Option Price per share specified in the Grant
Notice.

2. Option Term. This option shall have a maximum term of ten (10) years measured
from the Grant Date and shall accordingly expire at the close of business on the
expiration date specified in the Grant Notice, unless sooner terminated in
accordance with Paragraphs 5 or 6 of this Agreement.

3. Option Nontransferable; Exception. This option shall be neither transferable
nor assignable by Optionee other than by will or by the laws of descent and
distribution following the Optionee's death and may be exercised, during
Optionee's lifetime, only by Optionee.

4. Dates of Exercise. This option is exercisable for the Option Shares in one or
more installments as is specified in the Grant Notice. As this option becomes
exercisable in one or more installments, the installments shall accumulate and
this option shall remain exercisable for such installments until the expiration
date or the sooner termination of the option term under Paragraphs 5 or 6 of
this Agreement.


<PAGE>   17

5. Termination of Service.

                  (i) Should Optionee cease to remain in Service for any reason
         other than (a) Permanent Disability, (b) death or (c) for Cause, this
         option (to the extent otherwise exercisable on the date of such
         termination) shall be exercisable by Optionee at any time prior to the
         expiration date of the option (except as otherwise extended by the
         Committee) or within three (3) months after the date of such
         termination, whichever is the shorter period.

                  (ii) If Optionee's Service ceases by reason of Optionee's
         Permanent Disability, this option (to the extent otherwise exercisable
         on the date of such termination by reason of Permanent Disability)
         shall remain exercisable by Optionee at any time prior to the
         expiration date of this option (except as otherwise extended by the
         Committee) or within twelve (12) months after the date of such
         termination, whichever is the shorter period.

                  (iii) If Optionee's Service ceases as a result of death, this
         option (to the extent otherwise exercisable on the date of the death of
         Optionee) shall remain exercisable by the person or persons entitled to
         do so under Optionee's will or, if Optionee shall fail to make
         testamentary disposition of this option or shall die intestate, by
         Optionee's legal representative or representatives, at any time prior
         to the expiration date of this option (except as otherwise extended by
         the Committee) or within twelve (12) months after the date of such
         death, whichever is the shorter period.

                  (iv) If Optionee's Service ceases as a result of termination
         for Cause, then this option shall automatically terminate as of the
         termination date. As used herein, termination for "Cause" shall mean
         termination upon the occurrence of one or more of the following events:

                           (a) Optionee's failure to substantially perform his
                  duties with the Company or any Parent or Subsidiary
                  corporation as determined by the Committee in its sole
                  discretion following receipt by Optionee of written notice of
                  such failure and Optionee's failure to remedy such failure
                  within thirty (30) days after receipt of such notice (other
                  than failure from his incapacity during physical or mental
                  illness);

                           (b) Optionee's willful failure or refusal to perform
                  specific directives of the Board, which directives are
                  consistent with the scope and nature of Optionee's duties and
                  responsibilities, and which are not remedied by Optionee
                  within thirty (30) days after being notified in writing of his
                  failure by the Board;

                           (c) Optionee's conviction of a felony; or

                           (d) A breach of Optionee's fiduciary duty to the
                  Company or any Parent or Subsidiary corporation or willful
                  violation in the course of performing his duties for the
                  Company or any Parent or Subsidiary corporation of any law,
                  rule or



                                      -2-
<PAGE>   18

                  regulation (other than traffic violations or other minor
                  offenses). No act or failure to act on Optionee's part shall
                  be considered willful unless done or omitted to be done in bad
                  faith and without reasonable belief that the action or
                  omission was in the best interest of Company or any Parent or
                  Subsidiary corporation.

6. Corporate Transaction.

         A. In connection with a Corporate Transaction, the exercisability of
this option shall automatically accelerate so that this option shall,
immediately prior to the specified effective date for such Corporate
Transaction, become fully exercisable with respect to the Option Shares and may
be exercised for all or any portion of such Option Shares.

         B. Upon the consummation of the Corporate Transaction, this option
shall terminate and cease to be exercisable.

         C. The exercisability of this option as an Incentive Option under the
Federal tax laws (if designated as such in the Grant Notice) shall, in
connection with any such Corporate Transaction, be subject to the applicable
dollar limitation of Paragraph 21 of this Agreement.

         D. This Agreement shall not in any way affect the legal right of the
Company to adjust, reclassify, reorganize or otherwise make changes in its
capital or business structure or to merge, consolidate, dissolve, liquidate or
sell or transfer all or any part of its business or assets.

7. Adjustment in Option Shares. In the event that the Committee shall determine
that any dividend or other distribution (whether in the form of shares of Common
Stock or other securities), recapitalization, stock split, reverse stock split,
reorganization, merger, consolidation, split-up, spin-off, combination,
repurchase or exchange of securities of the Company, or other similar corporate
transaction or event affects the benefits or potential benefits intended to be
made available under this Plan such that an adjustment is determined by the
Committee to be appropriate in order to prevent dilution or enlargement of the
benefits or potential benefits intended to be made available under this option,
then the Committee may, in such manner as it may deem equitable, adjust any or
all of (i) the number of Option Shares subject to this option, (ii) the Option
Price payable hereunder and/or (iii) the nature of the consideration (including,
without limitation, other securities of the Company, securities of another
entity and/or other property); provided, however, in each case, that with
respect to Incentive Options no such adjustment shall be authorized to the
extent that such adjustment would cause the Plan or this option to violate
Section 422(b)(1) or 424(a) of the Code or any successor provisions thereto; and
provided further, however, that the number of Option Shares subject to this
option shall always be a whole number. Notwithstanding the foregoing,
Non-Statutory Options shall be subject to only such adjustment as shall be
necessary to maintain the proportionate interest of Optionee and preserve,
without exceeding, the value of this option.

8. Privilege of Stock Ownership. No shares of Common Stock shall be issued until
payment, as provided herein, therefor has been made. The Optionee shall not have
any of the rights of a



                                      -3-
<PAGE>   19

stockholder with respect to the Option Shares until such Optionee shall have
exercised this option and paid the Option Price.

9. Manner of Exercising Option.

         A. In order to exercise this option with respect to all or any part of
the Option Shares for which this option is at the time exercisable, the holder
of this option must take the following actions:

                  (i) Provide to the Company, in the written, telephonic, or
         electronic form designated by the Company, such information as is
         requested by the Company to determine the number of Option Shares with
         respect to which this option is exercised;

                  (ii) Pay the aggregate Option Price for the purchased Option
         Shares in cash (subject to the provisions of Paragraph 15 of this
         Agreement) or shares of Common Stock, other securities or other
         property, or any combination thereof, having a fair market value (as
         determined in accordance with the terms of this Agreement in the case
         of Common Stock and in all other cases by such methods or procedures as
         shall be authorized by the Committee) on the Exercise Date equal to the
         Option Price.

                  (iii) Furnish to the Company appropriate documentation that
         the person or persons exercising this option (if other than Optionee)
         have the right to exercise this option.

         B. As soon as practical following satisfaction of the foregoing
provisions of this Paragraph 9, the Company shall mail or deliver to Optionee
(or to the other person or persons exercising this option) a certificate or
certificates representing the Option Shares so purchased and paid for, with the
appropriate legends affixed thereto.

         C. In no event may this option be exercised for any fractional shares
of Common Stock.

10. Market Stand-Off Provisions.

         A. In connection with any underwritten public offering by the Company
of its equity securities pursuant to an effective registration statement filed
under the Securities Act of 1933, as amended (the "1933 Act"), Owner shall not
sell, make any short sale of, loan, hypothecate, pledge, grant any option for
the purchase of, or otherwise dispose or transfer for value or otherwise agree
to engage in any of the foregoing transactions with respect to any purchased
Option Shares without the prior written consent of the Company or its
underwriters. Such limitations shall be in effect for such period of time from
and after the effective date of such registration statement as may be requested
by the Company or such underwriters; provided, however, that in no event shall
such period exceed one hundred-eighty (180) days.



                                      -4-
<PAGE>   20

         B. Owner shall be subject to the market stand-off provisions of this
Paragraph 10 provided and only if the officers and directors of the Company are
also subject to similar arrangements.

         C. In the event of any stock dividend, stock split, recapitalization or
other change affecting the Company's outstanding Common Stock effected as a
class without receipt of consideration, then any new, substituted or additional
securities distributed with respect to purchased Option Shares shall be
immediately subject to the provisions of this Paragraph 10, to the same extent
purchased Option Shares are at such time covered by such provisions.

         D. In order to enforce the limitations of this Paragraph 10, the
Company may impose stop-transfer instructions with respect to purchased Option
Shares until the end of the applicable stand-off period.

11. Compliance with Laws and Regulations.

         A. The exercise of this option and the issuance of Option Shares upon
such exercise shall be subject to compliance by the Company and the Optionee
with all applicable requirements of law relating thereto and with all applicable
regulations of any stock exchange on which shares of the Common Stock may be
listed at the time of such exercise and issuance. Without limiting the
generality of the foregoing, this option may not be exercised and no Option
Shares may be transferred unless and until the Committee determines that such
exercise/transfer will be made in compliance with all applicable laws, rules and
regulations, including, without limitation, applicable securities laws, rules
and regulations. The Company does not have any obligation to take any action to
(i) register or qualify this option or any Option Shares pursuant to applicable
laws or to perfect an exemption from such registration/qualification
requirements or (ii) list the Option Shares for trading on any stock exchange or
automated transaction reporting system.

         B. In connection with the exercise of this option, Optionee shall
execute and deliver to the Company such representations in writing as may be
requested by the Company in order for it to comply with the applicable
requirements of Federal and state securities laws.

         C. Unless the issuance of purchased Option Shares to the Optionee has
been registered under the 1933 Act and all other applicable securities/blue sky
statutes, Optionee hereby confirms that Optionee has been informed that
purchased Option Shares are restricted securities under the 1933 Act and such
other securities/blue sky statutes and may not be resold or transferred unless
such shares are first registered under such act and such securities/blue sky
statutes or unless an exemption from such registration is available.
Accordingly, Optionee hereby acknowledges that Optionee is prepared to hold
purchased Option Shares for an indefinite period.

         D. In order to reflect the restrictions on disposition of purchased
Option Shares imposed by this Agreement, the stock certificates representing the
purchased Option Shares will be endorsed as applicable with one or more of the
following restrictive legends:



                                      -5-
<PAGE>   21

                  (i) "The shares represented by this certificate have not been
         registered under the Securities Act of 1933 or any other applicable
         securities laws. The shares may not be sold or offered for sale in the
         absence of (a) an effective registration statement for the shares under
         such Act and all other applicable securities laws, (b) a 'no action'
         letter of the Securities and Exchange Commission with respect to such
         sale or offer, or (c) satisfactory assurances to the Company that
         registration under such Act and all other applicable securities laws is
         not required with respect to such sale or offer."

                  (ii) "This certificate and the shares represented hereby may
         not be sold, assigned, transferred, encumbered, or in any manner
         disposed of except in conformity with the terms of a written agreement
         dated _________________, ______ between the Company and the registered
         holder of the shares (or the predecessor in interest to the shares).
         The Company will upon written request furnish a copy of such agreement
         to the holder hereof without charge."

12. Successors and Assigns. Except to the extent otherwise provided in Paragraph
3, the provisions of this Agreement shall inure to the benefit of, and be
binding upon, the successors, administrators, heirs, legal representatives and
assigns of Optionee and the successors and assigns of the Company, whether or
not any such person shall have become a party to this Agreement and have agreed
in writing to join herein and be bound by the terms and conditions hereof.

13. Liability of Company.

         A. If the Option Shares covered by this Agreement exceed, as of the
Grant Date, the number of shares of Common Stock which may without stockholder
approval be issued under the Plan, then this option shall be void with respect
to such excess shares, unless stockholder approval of an amendment sufficiently
increasing the number of shares of Common Stock issuable under the Plan is
obtained. If such stockholder approval is not obtained within twelve (12) months
after the date the amendment to the Plan is approved by the Board, then the
right to acquire any such excess shares evidenced by this Agreement shall
terminate.

         B. The inability of the Company to obtain approval from any regulatory
body having authority deemed by the Company to be necessary to the lawful
issuance and sale of any Common Stock pursuant to this option shall relieve the
Company of any liability with respect to the non-issuance or sale of the Common
Stock as to which such approval shall not have been obtained.

14. Notices. Any notice required to be given or delivered to the Company under
the terms of this Agreement shall be in writing and addressed to the Company in
care of the Corporate Secretary at the Company's principal corporate offices.
Any notice required to be given or delivered to Optionee shall be in writing and
addressed to Optionee at the address indicated below Optionee's signature line
on the Grant Notice. All notices shall be deemed to have been given or delivered
upon personal delivery or upon deposit in the U.S. mail, postage prepaid and
properly addressed to the party to be notified.



                                      -6-
<PAGE>   22

15. Loans. The Committee may, in its absolute discretion and without any
obligation to do so, assist the Optionee in the exercise of this option by (i)
authorizing the extension of a loan to the Optionee from the Company or (ii)
permitting the Optionee to pay the option price for the purchased Common Stock
in installments over a period of years. The terms of any such loan or
installment method of payment (including the interest rate, the requirements for
collateral and the terms of repayment) shall be established by the Committee in
its sole discretion.

16. Construction. This Agreement and the option evidenced hereby are made and
granted pursuant to the Plan and are in all respects limited by and subject to
the express terms and provisions of the Plan. Optionee hereby acknowledges
receipt of a copy of the Plan. All decisions of the Committee with respect to
any question or issue arising under the Plan or this Agreement shall be
conclusive and binding on all persons having an interest in this option.

17. Governing Law. The interpretation, performance, and enforcement of this
Agreement shall be governed by, and construed in accordance with, the laws of
the State of Texas, as such laws are applied to contracts entered into and
performed in such State without giving effect to the principles of conflict of
laws thereof. To the maximum extent practicable, this Agreement will be deemed
to call for performance in Dallas County, Texas.

18. No Waiver. No waiver of any breach or condition of this Agreement shall be
deemed to be a waiver of any other or subsequent breach or condition, whether of
like or different nature.

19. Optionee Undertaking. Optionee hereby agrees to take whatever additional
action and execute whatever additional documents the Company may in its judgment
deem necessary or advisable in order to carry out or effect one or more of the
obligations or restrictions imposed on either Optionee or purchased Option
Shares pursuant to the express provisions of this Agreement.

20. Agreement is Entire Contract. This Agreement, together with the Plan and the
Grant Notice, constitutes the entire contract between the parties hereto with
regard to the subject matter hereof. This Agreement may not be amended except by
written agreement of the parties hereto.

21. Additional Terms Applicable to an Incentive Option. In the event this
option is designated an Incentive Option in the Grant Notice, the following
terms and conditions shall also apply to the grant:

         A. This option shall cease to qualify for favorable tax treatment as an
Incentive Option under the Federal tax laws if (and to the extent) this option
is exercised for one or more Option Shares: (i) more than three (3) months after
the date the Optionee ceases to be an Employee for any reason other than death
or Permanent Disability or (ii) more than one (1) year after the date the
Optionee ceases to be an Employee by reason of Permanent Disability.

         B. The aggregate Fair Market Value (determined as of the Grant Date) of
the Option Shares for which this option first becomes exercisable together with
any option granted Optionee



                                      -7-
<PAGE>   23

under any other plan of the Company or any Parent or Subsidiary corporation as
incentive stock options under the Federal tax laws during any one calendar year
shall not exceed the sum of One Hundred Thousand Dollars ($100,000). To the
extent Optionee holds two or more such options which become exercisable for the
first time in the same calendar year, the foregoing limitation on the
exercisability thereof as Incentive Options under the Federal tax laws shall be
applied on the basis of the order in which such options are granted. In the
event the limits of this Paragraph 21B would otherwise be exceeded, Optionee may
still exercise the options, but such options, to the extent of such excess,
shall be deemed to be a Non-Statutory Option.

         C. In the event this option is designated as an installment option in
the Grant Notice, no installment under this option (whether annual or monthly)
shall qualify for favorable tax treatment as an Incentive Option under the
Federal tax laws if (and to the extent) the aggregate Fair Market Value
(determined at the Grant Date) of the Common Stock for which such installment
first becomes exercisable hereunder will, when added to the aggregate Fair
Market Value (determined as of the respective date or dates of grant) of the
Common Stock for which this option or one or more other Incentive Options
granted to the Optionee prior to the Grant Date (whether under the Plan or any
other option plan of the Company or any Parent or Subsidiary corporations) first
become exercisable during the same calendar year, exceed One Hundred Thousand
Dollars ($100,000) in the aggregate.

         D. Should the exercisability of this option be accelerated upon a
Corporate Transaction, then this option shall qualify for favorable tax
treatment as an Incentive Option under the Federal tax laws only to the extent
the aggregate Fair Market Value (determined at the Grant Date) of the Common
Stock for which this option first becomes exercisable in the calendar year in
which the Corporate Transaction occurs does not, when added to the aggregate
Fair Market Value (determined as of the respective date or dates of grant) of
the Common Stock for which this option or one or more other Incentive Options
granted to the Optionee prior to the Grant Date (whether under the Plan or any
other option plan of the Company or any Parent or Subsidiary corporations) first
become exercisable during the same calendar year, exceed One Hundred Thousand
Dollars ($100,000) in the aggregate.

         E. To the extent this option should fail to qualify as an Incentive
Option under the Federal tax laws, Optionee will recognize compensation income
in connection with the acquisition of one or more Option Shares hereunder, and
Optionee must make appropriate arrangements for the satisfaction of all Federal,
state or local income tax withholding requirements and Federal social security
employee tax requirements applicable to such compensation income.

22. Additional Terms Applicable to a Non-Statutory Option. In the event this
option is designated a Non-Statutory Option in the Grant Notice or as otherwise
provided in Paragraph 21 of this Agreement, Optionee hereby agrees to make
appropriate arrangements with the Company for the satisfaction of all Federal,
state or local income tax withholding requirements, Federal social security
employee tax requirements, Federal Medicare requirements and other similar
requirements applicable to the exercise of this option. The Company's obligation
to deliver Option Shares upon the exercise of this option shall be subject to
the satisfaction of all applicable Federal, State and local

                                       -8-
<PAGE>   24

income and employment tax withholding requirements. The Company or any Parent or
Subsidiary corporation that employs Optionee shall have the right to deduct any
sums that the Committee reasonably determines that Federal, State or local tax
law requires to be withheld with respect to the exercise of this option or as
otherwise may be required by those laws. Neither the Company nor any Parent or
Subsidiary corporation shall be obligated to advise Optionee of the existence of
the tax or the amount which the employer corporation will be so required to
withhold. Upon the exercise of a Non-Statutory Option, if tax withholding is
required, Optionee may, with the consent of the Committee, have Option Shares
withheld ("Share Withholding") by the Company from the Option Shares otherwise
to be received; provided, however, that if Optionee is subject to the provisions
of Section 16 under the Securities Exchange Act of 1934 (as amended) (the
"Exchange Act"), no Share Withholding shall be permitted unless such transaction
complies with the requirements of Rule 16b-3 promulgated under the Exchange Act.
The number of Option Shares so withheld should have an aggregate Fair Market
Value on the date of exercise sufficient to satisfy the applicable withholding
taxes.

23. Limited Stock Appreciation Right. Optionee is hereby granted a limited stock
appreciation right, exercisable upon the terms and conditions set forth below:

         A. The stock appreciation right shall become exercisable in connection
with a Change in Control. However, such right shall under no circumstances
become exercisable until it has been outstanding for a period of at least six
(6) months measured from the Grant Date of this option.

         B. Provided (i) the Optionee is at the time an officer or director of
the Company subject to the short-swing profit restrictions of the Federal
securities laws and (ii) one or more classes of the Company's equity securities
are at such time registered under Section 12 of the Exchange Act, then Optionee
shall have the right, exercisable for a thirty (30)-day period following the
completion of the Change in Control, to surrender this option (or any portion
thereof), to the extent such surrendered option (or portion thereof) is at the
time exercisable for vested Option Shares, for a cash distribution from the
Company equal in amount to the excess of (a) the aggregate Acquisition Price of
the number of Option Shares in which Optionee is at the time vested under the
surrendered option or portion thereof over (b) the aggregate Option Price
payable for such vested Option Shares.

         C. Should one or more of the Option Shares be unvested at the time of
the option surrender, then such Option Shares shall not be included within the
appreciation distribution payable by the Company, and this option shall continue
in effect for such unvested Option Shares. Accordingly, the Company shall issue
a new stock option agreement (substantially in the form of this Agreement) for
such unvested Option Shares as soon as practicable following the option
surrender.

         D. To effect the surrender of this option, the Optionee must provide
written notice to the Company, accompanied by the return of this Agreement and
all other instruments evidencing the surrendered option, prior to the expiration
of the applicable thirty (30)-day period.



                                      -9-
<PAGE>   25

         E. In no event may this limited stock appreciation right be exercised
when there is not a positive spread between the Fair Market Value of the Option
Shares and the aggregate Option Price payable for such Option Shares. This
limited stock appreciation right shall in all events terminate upon the
expiration or sooner termination of the option term and may not be assigned or
transferred by the Optionee.

24. Definitions. The following definitional provisions shall be in effect for
all purposes under this Agreement:

         Acquisition Price shall be the greater of (i) the Fair Market Value per
share on the date this option is surrendered pursuant to Paragraph 23 of this
Agreement or (ii) the highest reported price per share paid in effecting the
Change in Control of the Company's outstanding voting stock. However, if the
surrendered option is designated as an Incentive Option in the Grant Notice,
then the Acquisition Price of the vested Option Shares subject to the
surrendered option shall not exceed the Fair Market Value per share.

         Board means the Board of Directors of the Company.

         Change in Control means the acquisition of fifty percent (50%) or more
of the Company's outstanding voting stock pursuant to a tender or exchange offer
made by a person or group of related persons (other than the Company or a person
that directly or indirectly controls, is controlled by or is under common
control with the Company) which the Board does not recommend to the Company's
stockholders.

         Code means the Internal Revenue Code of 1986, as amended.

         Committee means the Stock Option Committee of the Board which shall be
comprised of two (2) or more directors, each of whom shall be a "non-employee
director," as defined in Rule 16b-3, promulgated under the Exchange Act.

         Common Stock means the Class A Convertible Common Stock, par value
$.0001 per share, of the Company.

         Company means PageMart Wireless, Inc., a Delaware corporation.

         Corporate Transaction means one or more of the following
stockholder-approved transactions:

                  (i) a merger or consolidation in which the Company is not the
         surviving entity, provided securities possessing fifty percent (50%) or
         more of the total combined voting power of the Company's outstanding
         voting securities are transferred to holders different from those who
         held such securities immediately prior to such transaction,



                                      -10-
<PAGE>   26
                  (ii) the sale, transfer or other disposition of all or
         substantially all of the assets of the Company, or

                  (iii) any reverse merger in which the Company is the surviving
         entity but in which securities possessing fifty percent (50%) or more
         of the total combined voting power of the Company's outstanding voting
         securities are transferred to holders different from those who held
         such securities immediately prior to such merger.

In no event shall any merger, consolidation or other reorganization involving
the Company be deemed to constitute a Corporate Transaction if the primary
purpose of such transaction is either to change the state in which the Company
is incorporated or to create a holding-company structure whereby the Company's
stockholders of record become the stockholders of record of the holding company.

         Employee means an individual who is in the employ of the Company or any
Parent or Subsidiary corporation. An Optionee shall be considered to be an
Employee for so long as such individual remains in the employ of the Company or
any Parent or Subsidiary corporation, subject to the control and direction of
the employer entity as to both the work to be performed and the manner and
method of performance.

         Exercise Date shall be date on which the option is exercised for one or
more Option Shares and payment for the Option Price is delivered to the Company
in accordance with Paragraph 9 of this Agreement.

         Fair Market Value of a share of Common Stock on any relevant date shall
be determined in accordance with the following provisions:

                  (i) If the Common Stock is not at the time listed or admitted
         to trading on any national securities exchange but is traded in the
         over-the-counter market, the Fair Market Value shall be the mean
         between the highest bid and the lowest asked prices (or if such
         information is available the closing sales price) per share of Common
         Stock on the date in question in the over-the-counter market, as such
         prices are reported by the National Association of Securities Dealers
         through its Nasdaq National Market System or any successor system. If
         there are no reported bid and asked prices (or closing sales price) for
         the Common Stock on the date in question, then the mean between the
         highest bid and lowest asked prices (or closing sales price) on the
         last preceding date for which such quotations exist shall be
         determinative of Fair Market Value.

                  (ii) If the Common Stock is at the time listed or admitted to
         trading on any national securities exchange, then the Fair Market Value
         shall be the closing sales price per share of Common Stock on the date
         in question on the national securities exchange determined by the
         Committee to be the primary market for the Common Stock, as such price
         is officially quoted in the composite tape of transactions on such
         exchange. If there is no



                                      -11-
<PAGE>   27

         reported sale of Common Stock on such exchange on the date in question,
         then the Fair Market Value shall be the closing sales price on the
         exchange on the last preceding date for which such quotation exists.

                  (iii) If the Common Stock is at the time neither listed nor
         admitted to trading on any national securities exchange nor traded in
         the over-the-counter market, or if the Committee otherwise determines
         that the valuation provisions of subparagraphs (i) and (ii) above will
         not result in a true and accurate valuation of the Common Stock, then
         the Fair Market Value shall be determined by the Committee after taking
         into account such factors as the Committee shall deem appropriate under
         the circumstances.

         Grant Date means the date specified in the Grant Notice as the date on
which the option was granted to the Optionee under the Plan.

         Grant Notice means the Notice of Grant of Stock Option which
accompanies this Agreement.

         Incentive Option means an incentive stock option which satisfies the
requirements of Section 422 of the Code.

         Non-Statutory Option means an option that does not meet (whether at the
time of grant of such option or subsequently) the statutory requirements
prescribed for an Incentive Option.

         Option Shares means the total number of shares of Common Stock
indicated in the Grant Notice as purchasable under this option.

         Optionee means the individual identified in the Grant Notice as the
person to whom this option has been granted under the Plan.

         Option Price means the exercise price per share to be paid by the
Optionee for the exercise of this option. The Option Price is indicated in the
Grant Notice.

         Owner means, for purposes of Paragraph 10 of this Agreement, Optionee
and all subsequent holders of purchased Option Shares who derive their chain of
ownership through a transfer from Optionee.

         Parent corporation means any corporation which, directly or indirectly,
owns, at the time of the determination, stock possessing fifty percent (50%) or
more of the total combined voting power of all classes of stock of the Company.

         Permanent Disability shall have the meaning set forth in Section
22(e)(3) of the Code, or any successor provision thereto.

         Plan means the Fifth Amended and Restated 1991 Stock Option Plan of the
Company.



                                      -12-
<PAGE>   28

         Service means the performance of services for the Company or any Parent
or Subsidiary corporation by an individual in the capacity of an Employee or a
non-employee member of the Board or the board of directors of such Parent or
Subsidiary corporation. Accordingly, the Optionee shall be deemed to remain in
Service for so long as such individual renders services to the Company or any
Parent or Subsidiary corporation on a periodic basis in the capacity of an
Employee or a non-employee member of the Board or the board of directors of such
Parent or Subsidiary corporation.

         Subsidiary corporation means any corporation of which the Company,
directly or indirectly, owns, at the time of the determination, stock possessing
fifty percent (50%) or more of the total combined voting power of all classes of
stock of the corporation in question.



                                      -13-
<PAGE>   29

                                    EXHIBIT B

                         NOTICE OF GRANT OF STOCK OPTION




<PAGE>   30
                                                 NOTICE OF GRANT OF STOCK OPTION
                                                        SPECIAL VESTING SCHEDULE


                             WEBLINK WIRELESS, INC.
                         NOTICE OF GRANT OF STOCK OPTION

         Notice is hereby given of the following stock option grant (the
"Option") to purchase shares of the Common Stock of WebLink Wireless, Inc. (the
"Company"):


                          Optionee:                   ((OPTIONEE))

                          Grant Date:                 ((grant))

                          Option Price:               ((price))per share

                          Number of Option Shares:    ((shares)) shares

                          Expiration Date:            ((expiration))

                          Type of Option:             Incentive Option
                                                -----

                                                      Non-Statutory Option
                                                -----


         Vesting Schedule: The Option shall vest and become exercisable on the
         date(s) and with respect to the number of shares of Common Stock set
         forth in EXHIBIT C provided the Optionee remains in continuous Service
         from the Grant Date to the applicable vesting date. In no event will
         the Option become vested and exercisable with respect to additional
         shares of Common Stock after the Optionee's termination of Service. If
         the Option becomes exercisable over more than one installment, the
         number of shares set forth in EXHIBIT C for each additional installment
         designates the number of additional shares of Common Stock for which
         the Option becomes exercisable on the applicable vesting date.

         Option Subject to Plan and Option Agreement. Optionee understands and
         agrees that the Option is granted subject to and in accordance with the
         express terms and conditions of the Company's Fifth Amended and
         Restated 1991 Stock Option Plan (the "Plan"). All capitalized terms not
         otherwise defined herein shall have the meaning set forth in the Plan.
         Optionee further agrees to be bound by the terms and conditions of the
         Plan and the terms and conditions of the Option as set forth in the
         Stock Option Agreement attached hereto as EXHIBIT A. Optionee hereby
         acknowledges receipt of a copy of the Plan in the form attached hereto
         as EXHIBIT B.

         No Employment or Service Contract. Nothing in this Notice or in the
         Plan or the Stock Option Agreement shall confer upon the Optionee any
         right to continue in the Service of the Company for any period of
         specific duration or interfere with or otherwise restrict in any way
         the rights of the Company or the Optionee, which rights are hereby
         expressly reserved by each, to terminate Optionee's Service at any time
         for any reason whatsoever, with or without cause.


<PAGE>   31
                                                 NOTICE OF GRANT OF STOCK OPTION
                                                        SPECIAL VESTING SCHEDULE


Dated as of :((grant))


                                          WEBLINK WIRELESS, INC.



                                          By:
                                             -----------------------------------

                                          Title:
                                                --------------------------------



                                          OPTIONEE


                                          --------------------------------------

                                Address:
                                          --------------------------------------

                                          --------------------------------------




                                       2
<PAGE>   32
                                                 NOTICE OF GRANT OF STOCK OPTION
                                                        SPECIAL VESTING SCHEDULE


                             PAGEMART WIRELESS, INC.
                         NOTICE OF GRANT OF STOCK OPTION

         Notice is hereby given of the following stock option grant (the
"Option") to purchase shares of the Common Stock of PageMart Wireless, Inc. (the
"Company"):

                          Optionee:                   ((OPTIONEE))

                          Grant Date:                 ((grant))

                          Option Price:               ((price))per share

                          Number of Option Shares:    ((shares)) shares

                          Expiration Date:            ((expiration))

                          Type of Option:             Incentive Option
                                                -----

                                                      Non-Statutory Option
                                                -----

         Vesting Schedule: The Option shall vest and become exercisable in its
         entirety on ________________, provided the Optionee remains in
         continuous Service from the Grant Date to such date. If Optionee's
         Service is terminated before ________________due to Optionee's death or
         disability or by the Company for a reason other than cause (as defined
         below), then immediately prior to such termination of Service the
         Option shall vest and become exercisable with respect to the total
         number of shares shown on EXHIBIT C as vesting on or before the date of
         termination of Service. In no event will the Option become vested and
         exercisable with respect to additional shares of Common Stock after the
         Optionee's termination of Service. If before ____________________
         Optionee terminates his Service voluntarily or the Company terminates
         his Service for cause, the Option will terminate without vesting.
         "Cause" means the occurrence of one or more of the events set forth in
         Sections 1(d)(iv)(B), (C) or (D) of the Plan (as defined below), but
         not the events set forth in Section 1(d)(iv)(A).

         Option Subject to Plan and Option Agreement. Optionee understands and
         agrees that the Option is granted subject to and in accordance with the
         express terms and conditions of the Company's Fifth Amended and
         Restated 1991 Stock Option Plan (the "Plan"). All capitalized terms not
         otherwise defined herein shall have the meaning set forth in the Plan.
         Optionee further agrees to be bound by the terms and conditions of the
         Plan and the terms and conditions of the Option as set forth in the
         Stock Option Agreement attached hereto as EXHIBIT A. Optionee hereby
         acknowledges receipt of a copy of the Plan in the form attached hereto
         as EXHIBIT B. This Notice of Grant of Stock Option supersedes any
         previous Notice of Grant of Stock Option with respect to the Option.

         No Employment or Service Contract. Nothing in this Notice or in the
         Plan or the Stock Option Agreement shall confer upon the Optionee any
         right to continue in the Service of the Company for any period of
         specific duration or interfere with or otherwise restrict in any

                                       3
<PAGE>   33
                                                 NOTICE OF GRANT OF STOCK OPTION
                                                        SPECIAL VESTING SCHEDULE


         way the rights of the Company or the Optionee, which rights are hereby
         expressly reserved by each, to terminate Optionee's Service at any time
         for any reason whatsoever, with or without cause.


Dated as of :((grant))


                                          PAGEMART WIRELESS, INC.



                                          By:
                                             -----------------------------------

                                          Title:
                                                --------------------------------



                                          OPTIONEE


                                          --------------------------------------

                                Address:
                                          --------------------------------------

                                          --------------------------------------



<PAGE>   34
                                                 NOTICE OF GRANT OF STOCK OPTION
                                                        SPECIAL VESTING SCHEDULE


                             WEBLINK WIRELESS, INC.
                         NOTICE OF GRANT OF STOCK OPTION

         Notice is hereby given of the following stock option grant (the
"Option") to purchase shares of the Common Stock of WebLink Wireless, Inc. (the
"Company"):


                           Optionee:    ((OPTIONEE))

                           Grant Date:    ((grant))

                           Vesting Commencement Date:    ((vesting))

                           Option Price:    ((price)) per share

                           Number of Option Shares:    ((shares)) shares

                           Expiration Date:    ((expiration))

                           Type of Option:         Incentive Option
                                             -----

                                                   Non-Statutory Option
                                             -----

         Vesting Schedule: Provided the Optionee remains in continuous Service
         from the Grant Date to the applicable vesting date, the Option shall
         become exercisable (i) with respect to 20% of the number of Option
         Shares designated above, on the first anniversary of the Vesting
         Commencement Date (the "Initial Vesting Date"); and (ii) with respect
         to the remaining balance of the number of Option Shares designated
         above, in equal, successive monthly installments over forty-eight (48)
         calendar months, beginning with the first calendar month following the
         Initial Vesting Date. The vesting date for each such calendar month
         ("Vesting Month") shall be the same day of the month as the Initial
         Vesting Date (or the last day of the Vesting Month if the Initial
         Vesting Date occurred on a day of the month that is greater than the
         last day of the Vesting Month). In no event will the Option become
         vested and exercisable with respect to additional shares of Common
         Stock after the Optionee's termination of Service.

         Option Subject to Plan and Option Agreement. Optionee understands and
         agrees that the Option is granted subject to and in accordance with the
         express terms and conditions of the Company's Fifth Amended and
         Restated 1991 Stock Option Plan (the "Plan"). All capitalized terms not
         otherwise defined herein shall have the meaning set forth in the Plan.
         Optionee further agrees to be bound by the terms and conditions of the
         Plan and the terms and conditions of the Option as set forth in the
         Stock Option Agreement attached hereto as EXHIBIT A. Optionee hereby
         acknowledges receipt of a copy of the Plan in the form attached hereto
         as EXHIBIT B.


                                       5
<PAGE>   35
                                                 NOTICE OF GRANT OF STOCK OPTION
                                                        SPECIAL VESTING SCHEDULE


         No Employment or Service Contract. Nothing in this Notice or in the
         Plan or the Stock Option Agreement shall confer upon the Optionee any
         right to continue in the Service of the Company for any period of
         specific duration or interfere with or otherwise restrict in any way
         the rights of the Company or the Optionee, which rights are hereby
         expressly reserved by each, to terminate Optionee's Service at any time
         for any reason whatsoever, with or without cause.


Dated as of :((grant))


                                          WEBLINK WIRELESS, INC.



                                          By:
                                             -----------------------------------

                                          Title:
                                                --------------------------------



                                          OPTIONEE


                                          --------------------------------------
                                          Signature of Optionee


                                Address:
                                          --------------------------------------

                                          --------------------------------------



                                        6