AVERT, INC.
                AMENDED AND RESTATED 1994 STOCK INCENTIVE PLAN
                INCENTIVE STOCK OPTION AGREEMENT

           This Agreement (the "Agreement") is made June 10, 1996, between
Avert, Inc., a Colorado Corporation (the "Company"), and Jerry D. Thurber (the
"Optionee"). The Company hereby grants the Optionee an option (the "Option") to
purchase Forty Thousand (40,000) of the Company's common shares, no par value
(the "Common Shares"), a purchase price (the "Option Price") of $6.50 per Common
Share. The Option has been granted pursuant to the Avert, Inc. Amended and
Restated 1994 Stock Incentive Plan (the "Plan") and shall include and be subject
to all provisions of the Plan, which are hereby incorporated herein by
reference, and shall be subject to the following provisions of the Agreement.

           1.   Terms and Vesting. Subject to the provisions of this Agreement,
                including but not limited to paragraph 6 hereof, and the Plan,
                this option may by exercised in blocks of 100 shares or any
                multiple thereof after the date of the Agreement and prior to
                5:00 p.m., on June 10, 2006, (the "Expiration Date") but not
                thereafter, in accordance with the following:

                   (a)  immediately on June 10, 1997, this option may be
                        exercised for up to 8,000 shares of the total Common
                        Shares covered hereby; and
                   (b)  immediately on June 10, of each of the four succeeding
                        years, this option may be exercised on each of those
                        dates for up to an additional 8,000 shares of the total
                        Common Shares covered hereby;

                   so that on and after June 10, 2001, and continuing until the
                   Expiration Date this option may be exercised for up to 100%
                   of the total Common Shares included in this option; provided,
                   however that notwithstanding the provisions of 1(a) or 1(b)
                   hereof, but subject to the further provisions of this
                   Agreement, if prior to June 10, 2001, Optionee's employment
                   with the Company is terminated by the company without cause
                   under the terms of the Employment Agreement between the
                   Company and the Optionee, dated as of June 10, 1996, and a
                   Change in Control as defined in the Plan has not occurred
                   thertofore, this Option may be exercised for


                                      (1)
 

 
               up to an additional 3,000 share of the total Common Shares
               covered hereby (or in the event such termination should occur
               prior to the first anniversary date of this Agreement and a
               Change in Control has not theretofor occurred, 3,000 shares of
               the total Common Shares covered hereby), effective on the date of
               such termination.
 
2.   Method of Exercise. Exercise of this option shall be affected by the
     Optionee giving written notice to the Company (in the form attached hereto
     as Exhibit A, whose covenants and substantive provisions are hereby made
     part of this Agreement) which shall:

               (a)  state that the Option is thereby being exercised, the number
                    of shares of Common Shares with respect to which the option
                    is being exercised, each person in whose name any
                    certificates for the Common Shares should be registered and
                    his or her address and social security number;
               (b)  be signed by the person or persons entitled to exercise the
                    Option and, if the Option is being exercised by anyone
                    other that the Optionee, be accompanied by proof
                    satisfactory to counsel for the Company of the right of such
                    person or persons to exercise the Option under the Plan and
                    all applicable laws and regulations; and
               (c)  be accompanied by such representations, warranties or
                    agreements with respect to the investment intent of such
                    person or persons exercising the Option as the Company may
                    reasonably request in form and substance satisfactory to
                    Counsel for the Company.

3.   Payment of Price. Upon exercise of the Option, the Company shall deliver a
     certificate or certificates for such Common Shares to the specified person
     or persons at the specified time upon receipt of the full purchase price
     for such Common Shares by any method of payment authorized by the Plan.

                                      (2)

 
4.   Transferability. The Option shall not be transferable by the Optionee
     except as expressly provided by the Plan. The Option shall be exercisable
     (subject to any other applicable restrictions on exercise) only by the
     Optionee for his own account, except in the events of the death or
     disability of the Optionee, in either of which events the Option shall be
     exercisable (subject to any other applicable restrictions on exercise) only
     by the Optionee's estate (acting through its fiduciary) or by the
     Optionee's duly authorized legal representative, respectively.


     5.   Restrictions on Exercise. The option is subject to all restrictions in
          the Agreement on in the Plan. As a condition of any exercise of the
          Option, the Company may require the Optionee or his successor to make
          any representation and warranty to comply with any applicable law or
          regulation or to confirm any factual matters reasonably requested by
          the counsel for the Company.

6.   Early Termination of Option. Notwithstanding paragraph 1 of this Agreement,
     the Option shall terminate, expire and become invalid and nonexercisable on
     the date three months following the date of termination of the Optionee's
     employment as an employee of the Company or a subsidiary corporation (other
     than by reason of death or permanent and total disability within the
     meaning of Section 22(e) 3) of the Internal Revenue Code of 1986, as
     amended (the "Code").

7.   Taxes. The Optionee hereby agrees to pay to the Company, in accordance with
     the terms of the Plan, any federal, state or local taxes of any kind
     required by law to be withheld with respect to the Option granted
     hereunder. If the Optionee does not make such payments to the Company, the
     Company shall have the right to withhold from any payments of any kind
     otherwise due to the Optionee from the Company, and federal, state or local
     taxes of any kind required by law to be withheld with respect to the Option
     or the Common Shares to be purchased by the Optionee under this Agreement.
     The Option shall be treated as an incentive stock option under Section 422
     or any successor section thereto of the Code.
 

                                      (3)

 
          8. Investment Representation. The Optionee agrees that any Common
             Shares of the Company which the Optionee may acquire by virtue of
             this Option shall be acquired for investment purposes only and not
             with a view to distribution or resale, and may not be transferred,
             sold, assigned, pledged, hypothecated or otherwise disposed of by
             the Optionee unless (I) a registration statement or post-effective
             amendment to a registration statement under the Securities Act of
             1933 as amended (the "Securities Act"), with respect to said Common
             Shares has become effective so as to permit the sale or other
             disposition of said shares by the Optionee; or (II) there is
             presented to the Company an opinion of Counsel satisfactory to the
             Company to the effect that the sale or other proposed disposition
             of said shares by the Optionee may lawfully be made otherwise than
             pursuant to an effective registration statement or post-effective
             amendment to a registration statement relating to the said shares
             under the Securities Act.
 
          9. Consent to Jurisdiction. The Optionee hereby consents to the
             jurisdiction of the state court of general jurisdiction sitting in
             Larimer County, Colorado, to resolve all questions arising under or
             out of this Agreement.

         10. Definitions. Unless otherwise defined in the Agreement, capitalized
             terms will have the same meaning given to them in the Plan.

DATE OF GRANT: June 10, 1996                        By:________________________
                                                    Dean A. Suposs, President

                     ACCEPTANCE OF AGREEMENT

          The Optionee hereby; (a) acknowledges receiving a copy of the Plan,
          which is attached to this Agreement, and represents that he is
          familiar with all provisions of the Plan; (b) accepts this Agreement
          and the Option granted to him under this Agreement subject to all
          provisions of the Plan and this Agreement:; and (c ) agrees to accept
          as binding, conclusive and final all decisions or interpretations of
          the Company.
 
              DATED_____________   ________________________________
                                   Jerry D. Thurber

 

                                      (4)