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                                                                   Exhibit 10.17

                              PHARSIGHT CORPORATION

                             1997 STOCK OPTION PLAN

                            Adopted February 17, 1997
                   Approved by the Shareholders March 17, 1997
                              Amended May 11, 1998
                              Amended May 14, 1999
                           Amended September 15, 1999
                              Amended April 7, 2000

1.    PURPOSES.

      (a) The purpose of the Plan is to provide a means by which selected
Employees and Directors of and Consultants to the Company, and its Affiliates,
may be given an opportunity to purchase stock of the Company.

      (b) The Company, by means of the Plan, seeks to retain the services of
persons who are now Employees or Directors of or Consultants to the Company or
its Affiliates, to secure and retain the services of new Employees, Directors
and Consultants, and to provide incentives for such persons to exert maximum
efforts for the success of the Company and its Affiliates.

      (c) The Company intends that the Options issued under the Plan shall, in
the discretion of the Board or any Committee to which responsibility for
administration of the Plan has been delegated pursuant to subsection 3(c), be
either Incentive Stock Options or Nonstatutory Stock Options. All Options shall
be separately designated Incentive Stock Options or Nonstatutory Stock Options
at the time of grant, and in such form as issued pursuant to Section 6, and a
separate certificate or certificates will be issued for shares purchased on
exercise of each type of Option.

2.    DEFINITIONS.

      (a) "Affiliate" means any parent corporation or subsidiary corporation,
whether now or hereafter existing, as those terms are defined in Sections 424(e)
and (f) respectively, of the Code.

      (b) "Board" means the Board of Directors of the Company.

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

      (d) "Committee" means a Committee appointed by the Board in accordance
with subsection 3(c) of the Plan.

      (e) "Company" means Pharsight Corporation, a California corporation.

      (f) "Consultant" means any person, including an advisor, engaged by the
Company or an Affiliate to render consulting services and who is compensated for
such services, provided that the term "Consultant" shall not include Directors
who are paid only a director's fee by the Company or who are not compensated by
the Company for their services as Directors.

      (g) "Continuous Service" means that the service of an individual to the
Company, whether as an Employee, Director or Consultant, is not interrupted or
terminated. The Board or the


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chief executive officer of the Company may determine, in that party's sole
discretion, whether Continuous Service shall be considered interrupted in the
case of: (i) any leave of absence approved by the Board or the chief executive
officer of the Company, including sick leave, military leave, or any other
personal leave; or (ii) transfers between the Company, Affiliates or their
successors.

      (h) "Covered Employee" means the chief executive officer and the four (4)
other highest compensated officers of the Company for whom total compensation is
required to be reported to stockholders under the Exchange Act, as determined
for purposes of Section 162(m) of the Code.

      (i) "Director" means a member of the Board.

      (j) "Employee" means any person, including Officers and Directors,
employed by the Company or any Affiliate of the Company. Neither service as a
Director nor payment of a director's fee by the Company shall be sufficient to
constitute "employment" by the Company.

      (k) "Exchange Act" means the Securities Exchange Act of 1934, as amended.

      (l) "Fair Market Value" means, as of any date, the value of the common
stock of the Company determined as follows and in each case in a manner
consistent with Section 260.140.50 of Title 10 of the California Code of
Regulations.

            (1) If the common stock is listed on any established stock exchange
or traded on the Nasdaq National Market or the Nasdaq SmallCap Market, the Fair
Market Value of a share of common stock shall be the closing sales price for
such stock (or the closing bid, if no sales were reported) as quoted on such
exchange or market (or the exchange or market with the greatest volume of
trading in the Company's common stock) on the last market trading day prior to
the day of determination, as reported in The Wall Street Journal or such other
source as the Board deems reliable.

            (2) In the absence of such markets for the common stock, the Fair
Market Value shall be determined in good faith by the Board.

      (m) "Incentive Stock Option" means an Option intended to qualify as an
incentive stock option within the meaning of Section 422 of the Code and the
regulations promulgated thereunder.

      (n) "Listing Date" means the first date upon which any security of the
Company is listed (or approved for listing) upon notice of issuance on any
securities exchange, or designated (or approved for designation) upon notice of
issuance as a national market security on an interdealer quotation system if
such securities exchange or interdealer quotation system has been certified in
accordance with the provisions of Section 25100(o) of the California Corporate
Securities Law of 1968.

      (o) "Non-Employee Director" means a Director who either (i) is not a
current Employee or Officer of the Company or its parent or subsidiary, does not
receive compensation (directly or indirectly) from the Company or its parent or
subsidiary for services rendered as a consultant or in any capacity other than
as a Director (except for an amount as to which disclosure would not be required
under Item 404(a) of Regulation S-K promulgated pursuant to the Securities Act
("Regulation S-K")), does not possess an interest in any other transaction as to
which disclosure would be required under Item 404(a) of Regulation S-K, and is
not engaged in a business relationship as to which disclosure


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would be required under Item 404(b) of Regulation S-K; or (ii) is otherwise
considered a "non-employee director" for purposes of Rule 16b-3.

      (p) "Nonstatutory Stock Option" means an Option not intended to qualify as
an Incentive Stock Option.

      (q) "Officer" means a person who is an officer of the Company within the
meaning of Section 16 of the Exchange Act and the rules and regulations
promulgated thereunder.

      (r) "Option" means a stock option granted pursuant to the Plan.

      (s) "Option Agreement" means a written agreement between the Company and
an Optionee evidencing the terms and conditions of an individual Option grant.
Each Option Agreement shall be subject to the terms and conditions of the Plan.

      (t) "Optionee" means a person to whom an Option is granted pursuant to the
Plan or, if applicable, such other person who holds an outstanding Option.

      (u) "Outside Director" means a Director who either (i) is not a current
employee of the Company or an "affiliated corporation" (within the meaning of
the Treasury regulations promulgated under Section 162(m) of the Code), is not a
former employee of the Company or an "affiliated corporation" receiving
compensation for prior services (other than benefits under a tax qualified
pension plan), was not an officer of the Company or an "affiliated corporation"
at any time, and is not currently receiving direct or indirect remuneration from
the Company or an "affiliated corporation" for services in any capacity other
than as a Director, or (ii) is otherwise considered an "outside director" for
purposes of Section 162(m) of the Code.

      (v) "Plan" means this 1997 Stock Option Plan.

      (w) "Rule 16b-3" means Rule 16b-3 of the Exchange Act or any successor to
Rule 16b-3 as in effect with respect to the Company at the time discretion is
being exercised regarding the Plan.

      (x) "Securities Act" means the Securities Act of 1933, as amended.

3.    ADMINISTRATION.

      (a) The Plan shall be administered by the Board unless and until the Board
delegates administration to a Committee, as provided in subsection 3(c).

      (b) The Board shall have the power, subject to, and within the limitations
of, the express provisions of the Plan:

            (1) To determine from time to time which of the persons eligible
under the Plan shall be granted Options; when and how each Option shall be
granted; whether an Option will be an Incentive Stock Option or a Nonstatutory
Stock Option; the provisions of each Option granted (which need not be
identical), including the time or times such Option may be exercised in whole or
in part; and the number of shares for which an Option shall be granted to each
such person.


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            (2) To construe and interpret the Plan and Options granted under it,
and to establish, amend and revoke rules and regulations for its administration.
The Board, in the exercise of this power, may correct any defect, omission or
inconsistency in the Plan or in any Option Agreement, in a manner and to the
extent it shall deem necessary or expedient to make the Plan fully effective.

            (3) To amend the Plan or an Option as provided in Section 11.

            (4) Generally, to exercise such powers and to perform such acts as
the Board deems necessary or expedient to promote the best interests of the
Company.

      (c) The Board may delegate administration of the Plan to a committee of
the Board composed of not fewer than two (2) members (the "Committee"), all of
the members of which Committee may be, in the discretion of the Board,
Non-Employee Directors and/or Outside Directors. If administration is delegated
to a Committee, the Committee shall have, in connection with the administration
of the Plan, the powers theretofore possessed by the Board, including the power
to delegate to a subcommittee of two (2) or more Outside Directors any of the
administrative powers the Committee is authorized to exercise (and references in
this Plan to the Board shall thereafter be to the Committee or such a
subcommittee), subject, however, to such resolutions, not inconsistent with the
provisions of the Plan, as may be adopted from time to time by the Board. The
Board may abolish the Committee at any time and revest in the Board the
administration of the Plan. Additionally, prior to the Listing Date, and
notwithstanding anything to the contrary contained herein, the Board may
delegate administration of the Plan to any person or persons and the term
"Committee" shall apply to any person or persons to whom such authority has been
delegated. Notwithstanding anything in this Section 3 to the contrary, the Board
or the Committee may delegate to a committee of one or more members of the Board
the authority to grant Options to eligible persons who (1) are not then subject
to Section 16 of the Exchange Act and/or (2) are either (i) not then Covered
Employees and are not expected to be Covered Employees at the time of
recognition of income resulting from such Option, or (ii) not persons with
respect to whom the Company wishes to comply with Section 162(m) of the Code.

4.    SHARES SUBJECT TO THE PLAN.

      (a) Subject to the provisions of Section 10 relating to adjustments upon
changes in stock, the stock that may be sold pursuant to Options shall not
exceed in the aggregate three million eight hundred thousand (3,800,000) shares
of the Company's common stock. If any Option shall for any reason expire or
otherwise terminate, in whole or in part, without having been exercised in full,
the stock not purchased under such Option shall revert to and again become
available for issuance under the Plan.

      (b) The stock subject to the Plan may be unissued shares or reacquired
shares, bought on the market or otherwise.

5.    ELIGIBILITY.

      (a) Incentive Stock Options may be granted only to Employees. Nonstatutory
Stock Options may be granted only to Employees, Directors or Consultants.

      (b) No person shall be eligible for the grant of an Option if, at the time
of grant, such person owns (or is deemed to own pursuant to Section 424(d) of
the Code) stock possessing more than ten


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percent (10%) of the total combined voting power of all classes of stock of the
Company or of any of its Affiliates unless the exercise price of such Option is
at least one hundred ten percent (110%) of the Fair Market Value of such stock
at the date of grant and the Option is not exercisable after the expiration of
five (5) years from the date of grant.

      (c) Subject to the provisions of Section 10 relating to adjustments upon
changes in stock, no person shall be eligible to be granted Options covering
more than four hundred fifty thousand (450,000) shares of the Company's common
stock in any calendar year. This subsection 5(c) shall not apply prior to the
Listing Date and, following the Listing Date, shall not apply until (i) the
earliest of: (A) the first material modification of the Plan (including any
increase to the number of shares reserved for issuance under the Plan in
accordance with Section 4); (B) the issuance of all of the shares of common
stock reserved for issuance under the Plan; (C) the expiration of the Plan; or
(D) the first meeting of stockholders at which directors are to be elected that
occurs after the close of the third calendar year following the calendar year in
which occurred the first registration of an equity security under Section 12 of
the Exchange Act; or (ii) such other date required by Section 162(m) of the Code
and the rules and regulations promulgated thereunder.

6.    OPTION PROVISIONS.

      Each Option shall be in such form and shall contain such terms and
conditions as the Board shall deem appropriate. The provisions of separate
Options need not be identical, but each Option shall include (through
incorporation of provisions hereof by reference in the Option or otherwise) the
substance of each of the following provisions:

      (a) Term. No Option shall be exercisable after the expiration of ten (10)
years from the date it was granted.

      (b) Price. The exercise price of each Incentive Stock Option shall be not
less than one hundred percent (100%) of the Fair Market Value of the stock
subject to the Option on the date the Option is granted; the exercise price of
each Nonstatutory Stock Option shall be not less than eighty-five percent (85%)
of the Fair Market Value of the stock subject to the Option on the date the
Option is granted. Notwithstanding the foregoing, an Option (whether an
Incentive Stock Option or a Nonstatutory Stock Option) may be granted with an
exercise price lower than that set forth in the preceding sentence if such
Option is granted pursuant to an assumption or substitution for another option
in a manner satisfying the provisions of Section 424(a) of the Code.

      (c) Consideration. The purchase price of stock acquired pursuant to an
Option shall be paid, to the extent permitted by applicable statutes and
regulations, either (i) in cash at the time the Option is exercised, or (ii) at
the discretion of the Board or the Committee, at the time of the grant of the
Option, (A) by delivery to the Company of other common stock of the Company, (B)
according to a deferred payment or other arrangement (which may include, without
limiting the generality of the foregoing, the use of other common stock of the
Company) with the person to whom the Option is granted or to whom the Option is
transferred pursuant to subsection 6(d), or (C) in any other form of legal
consideration that may be acceptable to the Board. In the case of any deferred
payment arrangement, interest shall be compounded at least annually and shall be
charged at the minimum rate of interest necessary to avoid the treatment as
interest, under any applicable provisions of the Code, of any amounts other than
amounts stated to be interest under the deferred payment arrangement.


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      (d) Transferability. An Option shall not be transferable except by will or
by the laws of descent and distribution, and shall be exercisable during the
lifetime of the person to whom the Option is granted only by such person. A
Nonstatutory Stock Option granted after the Listing Date shall only be
transferable by the Optionee upon such terms and conditions as are set forth in
the Option Agreement for such Nonstatutory Stock Option, as the Board or the
Committee shall determine in its discretion. The person to whom the Option is
granted may, by delivering written notice to the Company, in a form satisfactory
to the Company, designate a third party who, in the event of the death of the
Optionee, shall thereafter be entitled to exercise the Option.

      (e) Vesting. The total number of shares of stock subject to an Option may,
but need not, be allotted in periodic installments (which may, but need not, be
equal). The Option Agreement may provide that from time to time during each of
such installment periods, the Option may become exercisable ("vest") with
respect to some or all of the shares allotted to that period, and may be
exercised with respect to some or all of the shares allotted to such period
and/or any prior period as to which the Option became vested but was not fully
exercised. The Option may be subject to such other terms and conditions on the
time or times when it may be exercised (which may be based on performance or
other criteria) as the Board may deem appropriate. The vesting provisions of
individual Options may vary but in each case will provide for vesting of at
least twenty percent (20%) per year of the total number of shares subject to the
Option; provided, however, that an Option granted to an officer, director or
consultant (within the meaning of Section 260.140.41 of Title 10 of the
California Code of Regulations) may become fully exercisable, subject to
reasonable conditions such as continued employment, at any time or during any
period established by the Company or of any of its Affiliates. The provisions of
this subsection 6(e) are subject to any Option provisions governing the minimum
number of shares as to which an Option may be exercised.

      (f) Securities Law Compliance. The Company may require any Optionee, or
any person to whom an Option is transferred under subsection 6(d), as a
condition of exercising any such Option, (1) to give written assurances
satisfactory to the Company as to the Optionee's knowledge and experience in
financial and business matters and/or to employ a purchaser representative
reasonably satisfactory to the Company who is knowledgeable and experienced in
financial and business matters, and that he or she is capable of evaluating,
alone or together with the purchaser representative, the merits and risks of
exercising the Option; and (2) to give written assurances satisfactory to the
Company stating that such person is acquiring the stock subject to the Option
for such person's own account and not with any present intention of selling or
otherwise distributing the stock. The foregoing requirements, and any assurances
given pursuant to such requirements, shall be inoperative if (i) the issuance of
the shares upon the exercise of the Option has been registered under a then
currently effective registration statement under the Securities Act, or (ii) as
to any particular requirement, a determination is made by counsel for the
Company that such requirement need not be met in the circumstances under the
then applicable securities laws. The Company may require the Optionee to provide
such other representations, written assurances or information which the Company
shall determine is necessary, desirable or appropriate to comply with applicable
securities and other laws as a condition of granting an Option to such Optionee
or permitting the Optionee to exercise such Option. The Company may, upon advice
of counsel to the Company, place legends on stock certificates issued under the
Plan as such counsel deems necessary or appropriate in order to comply with
applicable securities laws, including, but not limited to, legends restricting
the transfer of the stock.

      (g) Termination of Employment or Relationship as a Director or Consultant.
In the event an Optionee's Continuous Service terminates (other than upon the
Optionee's death or disability),


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the Optionee may exercise his or her Option (to the extent that the Optionee was
entitled to exercise it as of the date of termination) but only within such
period of time ending on the earlier of (i) the date three (3) months following
the termination of the Optionee's Continuous Service, or such longer or shorter
period, which shall not be less than thirty (30) days, specified in the Option
Agreement, or (ii) the expiration of the term of the Option as set forth in the
Option Agreement. If, at the date of termination, the Optionee is not entitled
to exercise his or her entire Option, the shares covered by the unexercisable
portion of the Option shall revert to and again become available for issuance
under the Plan. If, after termination, the Optionee does not exercise his or her
Option within the time specified in the Option Agreement, the Option shall
terminate, and the shares covered by such Option shall revert to and again
become available for issuance under the Plan.

      (h) Disability of Optionee. In the event an Optionee's Continuous Service
terminates as a result of the Optionee's disability, the Optionee may exercise
his or her Option (to the extent that the Optionee was entitled to exercise it
as of the date of termination), but only within such period of time ending on
the earlier of (i) the date twelve (12) months following such termination (or
such longer or shorter period, which in no event shall be less than six (6)
months, specified in the Option Agreement), or (ii) the expiration of the term
of the Option as set forth in the Option Agreement. If, at the date of
termination, the Optionee is not entitled to exercise his or her entire Option,
the shares covered by the unexercisable portion of the Option shall revert to
and again become available for issuance under the Plan. If, after termination,
the Optionee does not exercise his or her Option within the time specified
herein, the Option shall terminate, and the shares covered by such Option shall
revert to and again become available for issuance under the Plan.

      (i) Death of Optionee. In the event of the death of an Optionee during, or
within a period specified in the Option Agreement after the termination of, the
Optionee's Continuous Service, the Option may be exercised (to the extent the
Optionee was entitled to exercise the Option as of the date of death) by the
Optionee's estate, by a person who acquired the right to exercise the Option by
bequest or inheritance or by a person designated to exercise the option upon the
Optionee's death pursuant to subsection 6(d), but only within the period ending
on the earlier of (i) the date eighteen (18) months following the date of death
(or such longer or shorter period, which in no event shall be less than six (6)
months, specified in the Option Agreement), or (ii) the expiration of the term
of such Option as set forth in the Option Agreement. If, at the time of death,
the Optionee was not entitled to exercise his or her entire Option, the shares
covered by the unexercisable portion of the Option shall revert to and again
become available for issuance under the Plan. If, after death, the Option is not
exercised within the time specified herein, the Option shall terminate, and the
shares covered by such Option shall revert to and again become available for
issuance under the Plan.

      (j) Early Exercise. The Option may, but need not, include a provision
whereby the Optionee may elect at any time while an Employee, Director or
Consultant to exercise the Option as to any part or all of the shares subject to
the Option prior to the full vesting of the Option. Any unvested shares so
purchased shall be subject to a repurchase right in favor of the Company, with
the repurchase price to be equal to the original purchase price of the stock, or
to any other restriction the Board determines to be appropriate; provided,
however, that (i) the right to repurchase at the original purchase price shall
lapse at a minimum rate of twenty percent (20%) per year over five (5) years
from the date the Option was granted, and (ii) such right shall be exercisable
only within (A) the ninety (90) day period following the termination of
employment or the relationship as a Director or Consultant, or (B) such longer
period as may be agreed to by the Company and the Optionee (for example, for
purposes of satisfying the requirements of Section 1202(c)(3) of the Code
(regarding "qualified small business stock")), and (iii) such right shall be
exercisable only for cash or cancellation of purchase money


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indebtedness for the shares. Notwithstanding the foregoing, shares received on
exercise of an Option by an officer, director or consultant (within the meaning
of Section 260.140.41 of Title 10 of the California Code of Regulations) may be
subject to additional or greater restrictions.

      (k) Right of First Refusal. The Option may, but need not, include a
provision whereby the Company may elect, prior to the Listing Date, to exercise
a right of first refusal following receipt of notice from the Optionee of the
intent to transfer all or any part of the shares exercised pursuant to the
Option. Except as expressly provided in this Subsection (k), such right of first
refusal shall otherwise comply with the provisions of the Bylaws of the Company.

      (l) Withholding. To the extent provided by the terms of an Option
Agreement, the Optionee may satisfy any federal, state or local tax withholding
obligation relating to the exercise of such Option by any of the following means
or by a combination of such means: (1) tendering a cash payment; (2) authorizing
the Company to withhold shares from the shares of the common stock otherwise
issuable to the Optionee as a result of the exercise of the Option; or (3)
delivering to the Company owned and unencumbered shares of the common stock of
the Company.

7.    COVENANTS OF THE COMPANY.

      (a) During the terms of the Options, the Company shall keep available at
all times the number of shares of stock required to satisfy such Options.

      (b) The Company shall seek to obtain from each regulatory commission or
agency having jurisdiction over the Plan such authority as may be required to
issue and sell shares of stock upon exercise of the Options; provided, however,
that this undertaking shall not require the Company to register under the
Securities Act either the Plan, any Option or any stock issued or issuable
pursuant to any such Option. If, after reasonable efforts, the Company is unable
to obtain from any such regulatory commission or agency the authority which
counsel for the Company deems necessary for the lawful issuance and sale of
stock under the Plan, the Company shall be relieved from any liability for
failure to issue and sell stock upon exercise of such Options unless and until
such authority is obtained.

8.    USE OF PROCEEDS FROM STOCK.

      Proceeds from the sale of stock pursuant to Options shall constitute
general funds of the Company.

9.    MISCELLANEOUS.

      (a) Subject to any applicable provisions of the California Corporate
Securities Law of 1968 and related regulations relied upon as a condition of
issuing securities pursuant to the Plan, the Board shall have the power to
accelerate the time at which an Option may first be exercised or the time during
which an Option or any part thereof will vest pursuant to subsection 6(e),
notwithstanding the provisions in the Option stating the time at which it may
first be exercised or the time during which it will vest.

      (b) Neither an Optionee nor any person to whom an Option is transferred
under subsection 6(d) shall be deemed to be the holder of, or to have any of the
rights of a holder with respect to, any


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shares subject to such Option unless and until such person has satisfied all
requirements for exercise of the Option pursuant to its terms.

      (c) Throughout the term of any Option, the Company shall deliver to the
holder of such Option, not later than one hundred twenty (120) days after the
close of each of the Company's fiscal years during the Option term, a balance
sheet and an income statement. This section shall not apply (i) after the
Listing Date, or (ii) when issuance is limited to key employees whose duties in
connection with the Company assure them access to equivalent information.

      (d) Nothing in the Plan or any instrument executed or Option granted
pursuant thereto shall confer upon any Employee, Director, Consultant or
Optionee any right to continue in the employ of the Company or any Affiliate (or
to continue acting as a Director or Consultant) or shall affect the right of the
Company or any Affiliate to terminate the employment of any Employee, with or
without cause, to remove any Director as provided in the Company's Bylaws and
the provisions of the General Corporation Law of the State of California, or to
terminate the relationship of any Consultant subject to the terms of that
Consultant's agreement with the Company or Affiliate to which such Consultant is
providing services.

      (e) To the extent that the aggregate Fair Market Value (determined at the
time of grant) of stock with respect to which Incentive Stock Options are
exercisable for the first time by any Optionee during any calendar year under
all plans of the Company and its Affiliates exceeds one hundred thousand dollars
($100,000), the Options or portions thereof which exceed such limit (according
to the order in which they were granted) shall be treated as Nonstatutory Stock
Options.

      (f) (1) The Board or the Committee shall have the authority to effect, at
any time and from time to time (i) the repricing of any outstanding Options
under the Plan and/or (ii) with the consent of the affected holders of Options,
the cancellation of any outstanding Options and the grant in substitution
therefor of new Options under the Plan covering the same or different numbers of
shares of common stock, but having an exercise price per share not less than
eighty-five percent (85%) of the Fair Market Value (one hundred percent (100%)
of the Fair Market Value in the case of an Incentive Stock Option or, in the
case of a ten percent (10%) stockholder (as defined in subsection 5(b)), not
less than one hundred and ten percent (110%) of the Fair Market Value) per share
of common stock on the new grant date.

            (2) Shares subject to an Option canceled under this subsection 9(f)
shall continue to be counted, for the applicable period in which it was granted,
against the maximum award of Options permitted to be granted pursuant to
subsection 5(c) of the Plan. The repricing of an Option under this subsection
9(f), resulting in a reduction of the exercise price, shall be deemed to be a
cancellation of the original Option and the grant of a substitute Option; in the
event of such repricing, both the original and the substituted Options shall be
counted for the applicable period against the maximum awards of Options
permitted to be granted pursuant to subsection 5(c) of the Plan. The provisions
of this subsection 9(f)(2) shall be applicable only to the extent required by
Section 162(m) of the Code.

10.   ADJUSTMENTS UPON CHANGES IN STOCK.

      (a) If any change is made in the stock subject to the Plan, or subject to
any Option (through merger, consolidation, reorganization, recapitalization,
stock dividend, dividend in property other than cash, stock split, liquidating
dividend, combination of shares, exchange of shares, change in corporate
structure or other transaction not involving the receipt of consideration by the
Company), the Plan will


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be appropriately adjusted in the type(s) and maximum number of securities
subject to the Plan pursuant to subsection 4(a) and the maximum number of
securities subject to award to any person during any calendar year pursuant to
subsection 5(c), and the outstanding Options will be appropriately adjusted in
the type(s) and number of securities and price per share of stock subject to
such outstanding Options. Such adjustments shall be made by the Board or
Committee, the determination of which shall be final, binding and conclusive.
(The conversion of any convertible securities of the Company shall not be
treated as a "transaction not involving the receipt of consideration by the
Company.")

      (b) In the event of: (1) a dissolution, liquidation, or sale of all or
substantially all of the assets of the Company; (2) a merger or consolidation in
which the Company is not the surviving corporation; or (3) a reverse merger in
which the Company is the surviving corporation but the shares of the Company's
common stock outstanding immediately preceding the merger are converted by
virtue of the merger into other property, whether in the form of securities,
cash or otherwise, then: (i) any surviving or acquiring corporation shall assume
Options outstanding under the Plan or shall substitute similar options
(including an option to acquire the same consideration paid to stockholders in
the transaction described in this Subsection 10(b)) for those outstanding under
the Plan, or (ii) in the event any surviving or acquiring corporation refuses to
assume such Options or to substitute similar options for those outstanding under
the Plan, (A) with respect to Options held by persons then performing services
as Employees, Directors or Consultants and subject to any applicable provisions
of the California Corporate Securities Law of 1968 and related regulations
relied upon as a condition of issuing securities pursuant to the Plan, the
vesting of such Options and the time during which such Options may be exercised
shall be accelerated prior to such event and the Options terminated if not
exercised after such acceleration and at or prior to such event, and (B) with
respect to any other Options outstanding under the Plan, such Options shall be
terminated if not exercised prior to such event.

11.   AMENDMENT OF THE PLAN AND OPTIONS.

      (a) The Board at any time, and from time to time, may amend the Plan.
However, except as provided in Section 10 relating to adjustments upon changes
in stock, no amendment shall be effective unless approved by the stockholders of
the Company within twelve (12) months before or after the adoption of the
amendment, where the amendment will:

            (1) Increase the number of shares reserved for Options under the
Plan;

            (2) Modify the requirements as to eligibility for participation in
the Plan (to the extent such modification requires stockholder approval in order
for the Plan to satisfy the requirements of Section 422 of the Code); or

            (3) Modify the Plan in any other way if such modification requires
stockholder approval in order for the Plan to satisfy the requirements of
Section 422 of the Code or to comply with applicable stock exchange listing
requirements.

      (b) The Board may in its sole discretion submit any other amendment to the
Plan for stockholder approval, including, but not limited to, amendments to the
Plan intended to satisfy the requirements of Section 162(m) of the Code and the
regulations promulgated thereunder regarding the exclusion of performance-based
compensation from the limit on corporate deductibility of compensation paid to
certain executive officers.


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<PAGE>

      (c) It is expressly contemplated that the Board may amend the Plan in any
respect the Board deems necessary or advisable to provide Optionees with the
maximum benefits provided or to be provided under the provisions of the Code and
the regulations promulgated thereunder relating to Incentive Stock Options
and/or to bring the Plan and/or Incentive Stock Options granted under it into
compliance therewith.

      (d) Rights and obligations under any Option granted before amendment of
the Plan shall not be impaired by any amendment of the Plan unless (i) the
Company requests the consent of the person to whom the Option was granted and
(ii) such person consents in writing.

      (e) The Board at any time, and from time to time, may amend the terms of
any one or more Options; provided, however, that the rights and obligations
under any Option shall not be impaired by any such amendment unless (i) the
Company requests the consent of the person to whom the Option was granted and
(ii) such person consents in writing.

12.   TERMINATION OR SUSPENSION OF THE PLAN.

      (a) The Board may suspend or terminate the Plan at any time. Unless sooner
terminated, the Plan shall terminate on February 16, 2007, which shall be within
ten (10) years from the date the Plan is adopted by the Board or approved by the
stockholders of the Company, whichever is earlier. No Options may be granted
under the Plan while the Plan is suspended or after it is terminated.

      (b) Rights and obligations under any Option granted while the Plan is in
effect shall not be impaired by suspension or termination of the Plan, except
with the written consent of the person to whom the Option was granted.

13.   EFFECTIVE DATE OF PLAN.

      The Plan shall become effective as determined by the Board, but no Options
granted under the Plan shall be exercised unless and until the Plan has been
approved by the stockholders of the Company, which approval shall be within
twelve (12) months before or after the date the Plan is adopted by the Board.


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