EXHIBIT 4.12

                       SUBSCRIPTION AND PURCHASE AGREEMENT


         THIS SUBSCRIPTION AND PURCHASE AGREEMENT (the "Agreement") by and
between HEALTHWATCH, INC., a Minnesota corporation (the "Company"), and PAUL
HARRISON ENTERPRISES, INC., a Georgia corporation (the "Investor").

         In consideration of the mutual promises, representations, warranties,
covenants and conditions set forth in this Agreement, the Company and the
Investor mutually agree as follows:


                                    ARTICLE 1

                            DESCRIPTION OF FINANCING

         1.1 AUTHORIZATION OF THE SHARES. The Company has authorized the
issuance and sale of 2,000,000 shares of its Common Stock (the "HW Shares"), for
500,000 shares of Halis, Inc., a Georgia corporation ("Halis"), common stock
(the "Halis Shares"). In addition to the HW Shares to be acquired at the Closing
(as hereinafter defined), the Company has granted to Investor the right and
option (the "Option") described in Article 7 hereof to exchange up to an
additional 400,000 shares of Halis Common Stock for up to an additional
1,600,000 shares of the Company's Common Stock. The additional shares of the
Company's Common Stock to be exchanged for the additional shares of Halis Common
Stock are herein referred to as the "Option Shares."

         1.2 PURCHASE AND SALE OF SHARES. Subject to the terms and conditions of
this Agreement and in reliance upon the representations and warranties contained
herein, the Company agrees to sell the HW Shares to Investor for the Halis
Shares, and Investor agrees to purchase the HW Shares by the delivery and
transfer to the Company of the Halis Shares.

         1.3 CLOSING. Closing of the purchase and sale of the HW Shares shall
take place by mail or facsimile as soon as possible after the date hereof. At
the Closing, Investor shall deliver to the Company in payment for the HW Shares
one or more certificates for the Halis Shares duly endorsed for transfer to the
Company and the Company shall deliver one or more certificates for the HW Shares
to Investor in accordance with Investor's instructions.

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                                    ARTICLE 2

                  REPRESENTATIONS AND WARRANTIES OF THE COMPANY

         The Company hereby represents and warrants to the Investor that:

         2.1 DUE ORGANIZATION; ETC. The Company is a corporation duly organized,
validly existing and in good standing under the laws of the State of Minnesota
and has all necessary power and authority (i) to conduct its business in the
manner in which its business is currently being conducted and in the manner in
which its business is proposed to be conducted; (ii) to own and use its assets
in the manner in which its assets are currently owned and used and in the manner
in which its assets are proposed to be owned and used; and (iii) to perform its
obligations under this Agreement. The Company is qualified, authorized,
registered or licensed to do business as a foreign corporation in all
jurisdictions where such qualification, authorization, registration or license
is required, except where the failure to be so qualified, authorized, registered
or licensed has not had and will not have a material adverse effect on the
Company's business, condition, assets, liabilities, operations, financial
performance or prospects.

         2.2 CORPORATE POWER. The Company has all requisite legal and corporate
power and authority to execute and deliver this Agreement and to sell and issue
the HW Shares hereunder, and to carry out and perform its obligations under the
terms of this Agreement.

         2.3 CAPITALIZATION. The authorized stock of the Company consists of a
total of 14,285,715 authorized shares of common stock, of which no more than
4,250,000 shares, not including shares which may have been issued to Halis, will
be issued and outstanding at the Closing and a total of 1,428,571 authorized
shares of preferred stock, of which no more than 20,833 shares of Series H
Convertible Preferred Stock will be issued and outstanding at the Closing. The
outstanding shares of Common Stock have been duly authorized and validly issued,
and are or will be when issued fully paid and nonassessable.

         2.4 AUTHORIZATION. All corporate action on the part of the Company, its
officers, directors and shareholders necessary for the authorization, execution,
delivery and performance by the Company of this Agreement, the authorization,
sale, issuance and delivery of the HW Shares, and the performance of all the
Company's obligations hereunder has been taken or will be taken prior to
Closing. This Agreement, when executed and delivered by the Company, shall
constitute a valid and binding obligation of the Company. The HW Shares and
Option Shares, when issued in compliance with the provisions of this Agreement,
will be validly issued (including, without limitation, issued in compliance with
applicable federal and state securities laws), fully paid and nonassessable. The
HW Shares and Option Shares will be free of any liens or encumbrances and are
not subject to any preemptive rights.

<PAGE>


         2.5 SEC FILINGS; FINANCIAL STATEMENTS.

                  (a) The Company has delivered to Investor accurate and
         complete copies (excluding copies of exhibits) of its Annual Report on
         Form 10-KSB for the fiscal year ended June 30, 1996, and of a
         Prospectus dated June 30, 1997, filed by the Company with the
         Securities and Exchange Commission (the "SEC") (the "Company SEC
         Documents"). As of the time it was filed with the SEC (or, if amended
         or superseded by a filing prior to the date of this Agreement, then on
         the date of such filing):

                           (i) each of the Company SEC Documents complied in all
                  material respects with the applicable requirements of the
                  federal Securities Act of 1933, as amended, (the "1933 Act")
                  or the Securities Exchange Act of 1934, as amended (the "1934
                  Act") (as the case may be); and

                           (ii) none of the Company SEC Documents contained any
                  untrue statement of a material fact or omitted to state a
                  material fact required to be stated therein or necessary in
                  order to make the statements therein, in the light of the
                  circumstances under which they were made, not misleading.

                  (b) The financial statements contained in the Company SEC
         Documents:

                           (i) were prepared in accordance with generally
                  accepted accounting principles applied on a consistent basis
                  throughout the periods covered, except as may be indicated in
                  the notes to such financial statements and (in the case of
                  unaudited statements) as permitted by Form 10-QSB of the SEC,
                  and except that unaudited financial statements may not contain
                  footnotes and are subject to normal and recurring year-end
                  audit adjustments which will not, individually or in the
                  aggregate, be material in magnitude; and

                           (ii) fairly present the financial position of the
                  Company as of the respective dates thereof and the results of
                  operations of the Company for the periods covered thereby.

         2.6 ABSENCE OF CHANGES. Since June 30, 1997:

                  (a) the Company has not sold, exchanged or otherwise disposed
         of any material assets or rights or entered into any transaction which
         was not in the ordinary course of business, except for the Letter of
         Intent and Subscription and Purchase Agreement entered into with Halis;

                  (b) there has been no materially adverse change in the
         condition (financial or otherwise), of the business, property, assets
         or liabilities of the

<PAGE>


         Company other than changes in the ordinary course of business, none of
         which, individually or in the aggregate, has been materially adverse;
         and

                  (c) to the best knowledge of the Company, there has been no
         other event or condition of any character pertaining to and materially
         and adversely affecting the assets or business of the Company (as now
         conducted or as presently proposed to be conducted).

         2.7 LITIGATION. There is no action, suit, proceeding at law or in
equity by any person or entity, or any arbitration, or any administrative or
other proceeding by or before any governmental or other instrumentality or
agency pending, or, to the knowledge of the Company, threatened, against or
affecting the Company or any of its properties, assets or rights which could
have a material adverse effect on the Company's business, condition, assets,
liabilities, operations, financial performance or prospects.

         2.8 EXTENSION OF DEBENTURES. Prior to the Closing the Company shall
have obtained from the holders of the Company's 10% Convertible Senior
Debentures Due 1997 agreements extending the due date of such Debentures from
September 1, 1997 to March 1, 1998.

         2.9 HIGH RISK INVESTMENT; TRANSFER OF HALIS SHARES. The Company is
aware that an investment in the Halis Shares involves substantial risks and
should be considered only by a person able to withstand a total loss of such
investment. Further, while the Halis Shares, including any shares acquired upon
the exercise of the Option, will be transferred to the Company pursuant to an
effective registration under the 1933 Act, the Company understands that any
subsequent transfer or distribution of the Halis Shares by the Company may be
subject to Rule 144 promulgated by the SEC since Paul Harrison, a director of
the Company, is an affiliate and significant beneficial owner of securities of
Investor and of Halis. The Company represents and warrants that it will comply
with all applicable federal and state securities laws in connection with any
transfer or distribution of the Halis Shares, including any shares acquired upon
the exercise of the Option.


                                    ARTICLE 3

                   REPRESENTATIONS AND WARRANTIES OF INVESTOR

         Investor represents and warrants that:

         3.1 HIGH RISK INVESTMENT. The Investor is aware that investment in the
HW Shares and Option Shares involves substantial risks. The Investor represents
that Investor understands that an investment in this offering should be
considered only by a person able to withstand a total loss of such investment.

         3.2 AUTHORIZATION. All action on the part of the Investor necessary for
the authorization, execution, delivery and performance by the Investor of this
Agreement, the

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sale, issuance and delivery of the Halis Shares, and the performance of all the
Investor's obligations hereunder has been taken or will be taken prior to
closing. This Agreement, when executed and delivered by the Investor, shall
constitute a valid and binding obligation of the Investor. The Halis Shares,
when delivered in compliance with the provisions of this Agreement, will be
validly issued (including, without limitation, issued in compliance with
applicable federal and state securities laws), fully paid and nonassessable. The
Halis Shares will be free of any liens or encumbrances and are not subject to
any preemptive rights.

         3.3 SEC FILINGS; FINANCIAL STATEMENTS.

                  (a) Investor has delivered to the Company accurate and
         complete copies (excluding copies of exhibits) of the Halis Annual
         Report on Form 10-KSB for the fiscal year ended December 31, 1996, and
         of a Prospectus dated August 22, 1997, filed by Halis with the SEC (the
         "Halis SEC Documents"). To Investor's best knowledge and belief, as of
         the time it was filed with the SEC (or, if amended or superseded by a
         filing prior to the date of this Agreement, then on the date of such
         filing):

                           (i) each of the Halis SEC Documents complied in all
                  material respects with the applicable requirements of the
                  federal 1933 Act, or the 1934 Act (as the case may be); and

                           (ii) none of the Halis SEC Documents contained any
                  untrue statement of a material fact or omitted to state a
                  material fact required to be stated therein or necessary in
                  order to make the statements therein, in the light of the
                  circumstances under which they were made, not misleading.

                  (b) The financial statements contained in the Halis SEC
         Documents:

                           (i) were prepared in accordance with generally
                  accepted accounting principles applied on a consistent basis
                  throughout the periods covered, except as may be indicated in
                  the notes to such financial statements and (in the case of
                  unaudited statements) as permitted by Form 10-QSB of the SEC,
                  and except that unaudited financial statements may not contain
                  footnotes and are subject to normal and recurring year-end
                  audit adjustments which will not, individually or in the
                  aggregate, be material in magnitude; and

                           (ii) fairly present the financial position of Halis
                  as of the respective dates thereof and the results of
                  operations of Halis for the periods covered thereby.

         3.4 ABSENCE OF CHANGES. Except as disclosed in the HALIS SEC Documents,
to Investor's best knowledge and belief, since June 30, 1997:

<PAGE>


                  (a) Halis has not sold, exchanged or otherwise disposed of any
         material assets or rights;

                  (b) there has been no materially adverse change in the
         condition (financial or otherwise), of the business, property, assets
         or liabilities of Halis other than changes in the ordinary course of
         business, none of which, individually or in the aggregate, has been
         materially adverse; and

                  (c) to the best knowledge of the Investor, there has been no
         other event or condition of any character pertaining to and materially
         and adversely affecting the assets or business of Halis (as now
         conducted or as presently proposed to be conducted).

         3.5 LITIGATION. To Investor's best knowledge and belief, and except as
disclosed in the Halis SEC Documents, there is no action, suit, proceeding at
law or in equity by any person or entity, or any arbitration, or any
administrative or other proceeding by or before any governmental or other
instrumentality or agency pending, or, to the knowledge of the Investor,
threatened, against or affecting Halis or any of its properties, assets or
rights which could have a material adverse effect on Halis' business, condition,
assets, liabilities, operations, financial performance or prospects.

         3.6 NASD MATTERS. Neither the Investor nor any corporation or
organization of which Investor is an officer or partner, any corporation or
organization of which Investor, directly or indirectly, is the beneficial owner
of 10% or more of any class of equity securities, any trust or other estate in
which Investor has a substantial beneficial interest or as to which Investor
serves as trustee or in a similar fiduciary capacity is a member of the National
Association of Securities Dealers, Inc. ("NASD"), is affiliated with a member of
the NASD or is a person associated with a member of the NASD, it being
understood that affiliation or association includes ownership of 5% or more of
the equity securities of any such member.

         3.7 REGISTRATION OF HALIS SHARES. The Halis Shares to be exchanged for
the HW Shares, including the Halis Shares which may be exchanged for HW Shares
upon exercise of the Option, are subject to an effective Registration Statement
under the 1933 Act and will be transferred to the Company pursuant to such
Registration Statement and will not be "restricted" shares as defined in Rule
144 promulgated by the SEC. Any resale of the Halis Shares by HealthWatch will,
however, be subject to Rule 144 since Paul Harrison, a director of the Company,
is an affiliate and significant owner of securities of Investor and of Halis.


                                    ARTICLE 4

             FEDERAL AND OTHER SECURITIES LAWS; REGISTRATION RIGHTS

         4.1 INVESTMENT REPRESENTATIONS AND WARRANTIES. Investor further
represents and warrants that:

<PAGE>


                  (a) Investment Experience. The Investor represents that
         Investor has such knowledge and experience in financial and business
         matters as to be capable of evaluating the merits and risks of the
         investment, and has the ability to bear the economic risks of the
         investment and to make an informed investment decision with respect
         thereto. The Investor further represents that Investor has had, during
         the course of the transaction and prior to the purchase of the HW
         Shares, the opportunity to ask questions of and receive answers from,
         the Company concerning the terms and conditions of the offering and to
         obtain additional information (to the extent the Company possessed such
         information or could acquire it without unreasonable effort or expense)
         necessary to verify the accuracy of any information furnished to or to
         which Investor had access.

                  (b) Acquisition for Investment for Investor's Own Account.
         This Agreement is made with the Investor in reliance upon Investor's
         representation to the Company, which by its acceptance hereof the
         Investor hereby confirms that the HW Shares and Option Shares will be
         acquired for investment for Investor's own account, not as a nominee or
         agent and not with a view to the sale or distribution of any part
         thereof. Any resales of the Shares and Option Shares will be in
         conformity with applicable law. By executing this Agreement, Investor
         further represents that Investor does not have any contract,
         undertaking, agreement, or arrangement with any person in violation of
         any federal or state law to sell, transfer, or grant participations to
         such person, or to any third person, with respect to the HW Shares or
         Option Shares. Investor realizes that the basis for the exemption from
         the registration requirements of the 1933 Act relied upon by the
         Company in connection with the offering, may not be present if,
         notwithstanding such representation, the Investor has in mind merely
         acquiring the HW Shares for a fixed or determinable period and selling
         them in the future, and Investor hereby confirms the absence of any
         such intention.

                  (c) Transfer or Disposition of HW Shares and Option Shares.
         The Investor understands that the HW Shares and Option Shares may not
         be sold, transferred, or otherwise disposed of without registration
         under the 1933 Act, and that in the absence of an effective
         registration statement, or an exemption from such registration
         requirements, such securities must be held indefinitely. The Investor
         represents that, in the absence of an effective registration statement,
         it will sell, transfer, or otherwise dispose of such securities only in
         a manner consistent with the representations set forth herein and in
         accordance with the provisions of this Agreement.

         4.2 CERTIFICATE LEGENDS. The Investor agrees that all certificates
evidencing the HW Shares and Option Shares shall bear a legend in substantially
the following form, and by which the Investor agrees to be bound:

         THE SECURITY DESCRIBED HEREIN HAS NOT BEEN REGISTERED UNDER THE
         SECURITIES ACT OF 1933, AS AMENDED (THE "1933 ACT"), OR UNDER THE
         SECURITIES LAWS

<PAGE>


         OF ANY STATE. NO SALE OR DISTRIBUTION OF THIS SECURITY MAY BE EFFECTED
         WITHOUT AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO OR AN
         OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY THAT SUCH
         REGISTRATION IS NOT REQUIRED UNDER THE 1933 ACT AND APPLICABLE STATE
         BLUE SKY LAWS.

         4.3 STOP TRANSFER INSTRUCTION. The Company shall make a notation
regarding the restrictions on transfer of the HW Shares in its stock books, and
the Company shall not be required to transfer on its books any of such
securities that have been sold or transferred in violation of any of the
provisions of this Agreement, or to treat as the owner of such securities any
transferee to whom such securities have been so transferred.

         4.4 REGISTRATION. At anytime after June 30, 1998, the Company will
promptly, upon request of Investor, take all necessary steps to register, or
qualify, under the 1933 Act and the securities laws of such states as the
Investor may reasonably request, the HW Shares and Option Shares, provided,
however, that the Company shall not for any purpose be required to execute a
general consent to service of process or to qualify to do business as a foreign
corporation in any jurisdiction wherein it is not so qualified. The Company
shall be obligated to prepare, file and cause to become effective only one
registration statement pursuant to this Section 4.4 and to pay all costs and
expenses associated with such registration statement as provided in Section 4.5.
The Company shall, at its expense, keep effective and maintain any registration,
qualification, notification or approval specified in this Section 4.4 for a
period of up to two years.

         4.5 EXPENSES. With respect to the inclusion of securities in a
registration statement pursuant to Section 4.4, except as provided in the next
succeeding sentence, the Company shall bear all fees, costs and expenses
including, without limitation: all registration, filing and NASD fees, printing
expenses, fees and disbursements of counsel and accountants for the Company, and
legal fees and disbursements and other expenses of complying with state
securities laws of any jurisdictions in which the securities to be offered are
to be registered or qualified. Fees and disbursements of special counsel and
accountants for the Investor, underwriting discounts and commissions, and
transfer taxes for Investor and any other expenses relating to the sale of
securities by the Investor not expressly included above shall be borne by the
Investor.

         4.6 INDEMNIFICATION. The Company hereby indemnifies the Investor and
all officers and directors, if any, who control Investor, within the meaning of
Section 15 of the 1933 Act, against all losses, claims, damages, and liabilities
caused by or arising from (1) any untrue statement or alleged untrue statement
of a material fact contained in any Registration Statement or Prospectus (and as
amended or supplemented if the Company shall have furnished any amendments
thereof or supplements thereto), any Preliminary Prospectus or any state
securities law filings; (2) any omission or alleged omission to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading except insofar as such losses, claims, damages, or
liabilities are caused by any untrue statement or omission contained in
information

<PAGE>


furnished in writing to the Company by Investor expressly for use therein; and
Investor by Investor's acceptance hereof agrees that it will indemnify and hold
harmless the Company, each of its officers who signs such Registration
Statement, and each person, if any, who controls the Company, within the meaning
of Section 15 of the 1933 Act, with respect to losses, claims, damages, or
liabilities which are caused by any untrue statement or alleged untrue
statement, omission or alleged omission contained in information furnished in
writing to the Company by Investor expressly for use therein.


                                    ARTICLE 5

               CONDITIONS TO INVESTOR'S OBLIGATIONS AT THE CLOSING

         The obligations of the Investor under Section 1.2 of this Agreement are
subject to the fulfillment on or before the Closings of each of the following
conditions:

         5.1 REPRESENTATIONS AND WARRANTIES TRUE. The representations and
warranties of the Company contained in Article 2 shall be true on and as of the
Closing with the same force and effect as if they had been made on the date
thereof.

         5.2 PERFORMANCE. The Company shall have conformed and complied with all
agreements and conditions contained in this Agreement required to be performed
or complied with by it on or before the Closing.

         5.3 QUALIFICATIONS. All authorizations, approvals, or permits, if any,
of any governmental authority or regulatory body of any state, that are required
in connection with the lawful issuance and sale of the HW Shares pursuant to
this Agreement shall have been duly obtained and shall be effective on and as of
the Closing.

         5.4 NASDAQ LISTING. Immediately following the exchange of the HW Shares
and Halis Shares pursuant to this and other similar Subscription and Purchase
Agreements, the Company's net worth shall be in excess of $2,000,000, which
amount is sufficient to meet the current maintenance requirements for the
Company's Common Stock on the Nasdaq Small Cap Market.

         5.5 DELIVERY OF CERTIFICATES. The Investor shall have received one or
more certificates representing the HW Shares.


                                    ARTICLE 6

               CONDITIONS TO THE COMPANY'S OBLIGATIONS AT CLOSING

         The obligations of the Company under Section 1.2 of this Agreement are
subject to the fulfillment on or before the Closing of each of the following
conditions as to the Investor:

<PAGE>


         6.1 REPRESENTATIONS AND WARRANTIES TRUE ON THE CLOSING. The
representations and warranties of Investor contained in Articles 3 and 4 shall
be true on and as of the Closing with the same force and effect as if they had
been made at the Closing.

         6.2 QUALIFICATIONS. All authorizations, approvals, or permits, if any,
of any governmental authority or regulatory body of any state that are required
in connection with the lawful issuance and sale of the Halis Shares pursuant to
this Agreement shall have been duly obtained and shall be effective on and as of
the Closing.

         6.3 PAYMENT OF PURCHASE PRICE. Investor shall have delivered to the
Company the total consideration for the Halis Shares which the Investor is to
deliver at the Closing.


                                    ARTICLE 7

                                     OPTION

         7.1 OPTION. Investor is entitled, subject to the terms and conditions
hereinafter set forth, to acquire from the Company up to 1,600,000 shares of its
Common Stock (the "Option Shares"), upon presentation of the Subscription Form
(Exhibit B hereto) duly executed, at the principal office of the Company or at
such other office as shall have heretofore been designated by the Company, upon
exchange in payment therefor of one share of Halis Common Stock for every four
shares of the Company's Common Stock being so purchased. The term of this Option
shall commence on the closing date and terminate if not exercised prior thereto,
at 5:00 p.m. California time on April 10, 1998. This Option may be exercised
only to the extent that the percentage of the Company's outstanding shares of
Common Stock immediately following any such exercise beneficially owned by
Investor, Halis and all officers, directors and affiliates of either Investor or
Halis, not including any shares subject to this Option, does not exceed 48%.

         7.2 OPTION TERMS. This Option is subject to the following terms and
conditions:

         a. The purchase rights represented by this Option are exercisable at
the option of Investor, in whole at any time, or in part from time to time (but
not as to a fractional share of stock).

         b. The purchase price for each security purchasable pursuant to the
exercise of this Option shall be one fourth (1/4th) of a share of Halis Common
Stock per share of the Company's Common Stock to be acquired, such price being
sometimes hereinafter referred to as the "Base Purchase Price". The Base
Purchase Price and, from time to time, the number of securities subject to
purchase hereunder are subject to adjustment in certain circumstances provided
for below, and the Base Purchase Price, as it may be adjusted from time to time,
is hereinafter referred to as the "Purchase Price".

<PAGE>


                  (i) In case either the Company or Halis shall (1) pay a
         dividend in shares of its capital stock (other than an issuance of
         shares of capital stock to holders of Common Stock who have elected to
         receive a dividend in shares in lieu of cash), (2) subdivide its
         outstanding shares of Common Stock, (3) change its capital stock into
         the same or a different number of shares of any class or classes of
         stock, (4) reduce, consolidate or combine its outstanding shares of
         Common Stock into a smaller number of shares, or (5) issue by
         reclassification of its shares of Common Stock any shares of the
         Company or Halis, as the case may be, the Purchase Price in effect
         immediately prior thereto shall be adjusted to that amount as
         reasonably determined by the Company's Board of Directors to fairly
         protect the rights of the Investor hereunder.

                  (b) If at any time or from time to time there shall be a
         capital reorganization of the stock of the Company (other than a
         subdivision, combination, reclassification or exchange of shares
         provided for elsewhere herein) or a merger or consolidation of the
         Company with or into another corporation, or the sale of all or
         substantially all of the Company's properties and assets to any other
         person, provision shall be made as reasonably determined by the
         Company's Board of Directors so that the Investor shall thereafter be
         entitled to receive upon exercise of this Option, the number of shares
         of stock or other securities or property of the Company or of the
         successor corporation resulting from such merger or consolidation or
         sale, to which a holder of stock deliverable upon exercise of this
         Option would have been entitled on such capital reorganization, merger,
         consolidation or sale. If at any time or from time to time there shall
         be a capital reorganization of the stock of Halis (other than a
         subdivision, combination, reclassification or exchange of shares
         provided for elsewhere herein) or a merger or consolidation of Halis
         whether into another corporation, or the sale of all or substantially
         all of Halis' properties and assets to any other person, this Option
         shall terminate unless, in the sole discretion of the Company's Board
         of Directors, adjustment in the Purchase Price can be made which
         reasonably protects both the rights of the Company and the Investor
         hereunder. In the event that the Company's Board of Directors believes
         that such an adjustment can be made, the Purchase Price shall be as
         reasonably determined by the Board of Directors in connection
         therewith.

        3. Exercise of this Option shall be made by the surrender hereof by the
Investor to the Company at its principal office together with (a) the attached
Subscription Form designating the number of shares of Common Stock being
purchased, and (b) a certificate of common stock duly endorsed for transfer to
the Company representing the Halis Shares of Common Stock to be exchanged for
the Company's Shares of Common Stock. The Company shall thereafter promptly (in
any event within seven (7) business days after such exercise) issue certificates
for securities of the Company purchased at the Purchase Price in effect at the
time of such exercise. The Investor shall be deemed to be the record owner of
such securities as of the close of business on the date of such exercise. The
Investor shall not be entitled to receive a fractional share, but in lieu
thereof the Company shall pay in cash an amount equal to the

<PAGE>


market value of such fractional share if the stock has a market value, or if
not, the book value of such fractional share.


                                    ARTICLE 8

                                  MISCELLANEOUS

         8.1 SURVIVAL OF WARRANTIES. The warranties, representations and
covenants contained in or made pursuant to this Agreement shall survive the
execution and delivery of this Agreement and the Closing and shall in no way be
affected by any investigation of the subject matter thereof made by or on behalf
of the Company or the Investor, as the case may be.

         8.2 ENTIRE AGREEMENT. This Agreement constitutes the entire agreement
between the parties with respect to the subject matter hereof and no party shall
be liable or bound to another party in any manner by any warranties,
representations or covenants except as specifically set forth herein or therein.
The terms and conditions of this Agreement shall inure to the benefit of and be
binding upon the respective successors and assigns of the parties. Nothing in
this Agreement, express or implied, is intended to confer upon any third party
any rights, remedies, obligations, or liabilities under or by reason of this
Agreement, except as expressly provided in this Agreement.

         8.3 GOVERNING LAW. This Agreement shall be governed by and construed
under the laws of the State of Georgia without regard to principles of conflicts
of laws.

         8.4 TITLES AND SUBTITLES. The titles and subtitles used in this
Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

         8.5 NOTICES. Any notice required or permitted under this Agreement
shall be given in writing and shall be deemed effectively given upon personal
delivery or seven (7) days after deposit with the United States Post Office, by
registered or certified mail, postage prepaid, addressed to the Company at 2445
Cades Way, Vista, California 92083, and to the Investor at the address specified
below or at such other address as a party may designate by ten (10) days'
advance written notice to the other party.

         8.6 EXPENSES. The Company shall pay all costs and expenses that it
incurs with respect to the negotiation, execution, delivery and performance of
the offering, and Investor shall pay all costs and expenses that it incurs with
respect to the negotiation, execution, delivery and performance of this
Agreement.

         8.7 SEVERABILITY. If one or more provisions of this Agreement are held
to be unenforceable under applicable law, such provisions shall be excluded from
this Agreement, and the balance of this Agreement shall be interpreted as if
such provisions were so excluded and shall be enforceable in accordance with its
terms.

<PAGE>


         8.8 COUNTERPARTS. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.


Entered into as of the 10th day of October, 1997.


                                     PAUL HARRISON ENTERPRISES, INC.


                                     By /s/ Paul Harrison
                                        ---------------------------------------
                                            Its President

                                     3390 Peachtree Road N.E.
                                     Suite 100
                                     Lenox Towers
                                     Atlanta, Georgia  30326
                                     (Mailing Address)


                                     HEALTHWATCH, INC.


                                     By:
                                        ---------------------------------------
                                            Its
                                                -------------------------------

<PAGE>


                                    EXHIBIT A

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

                                SUBSCRIPTION FORM

               To be signed only upon exercise of Option

         The undersigned hereby irrevocably elects to exercise the purchase
right represented by the Option described in Article 7 of the Subscription and
Purchase Agreement dated October 10, 1997 between the undersigned and
HealthWatch, Inc. for and to purchase thereunder, __________ of the shares of
Common Stock of HealthWatch, Inc., to which such Option relates, and herewith
makes payment therefor by the exchange and transfer to HealthWatch, Inc. of
_________ shares of the Common Stock of Halis, Inc. and requests that the
certificates for such shares be issued in the name of, and be delivered to,
________________, the address for which is set forth below the signature of the
undersigned.

Dated:
      -------------------

                                         ---------------------------------------
                                         (Signature)

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


                                         ---------------------------------------
                                         (Address)

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