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                                                                       Exhibit A

                          FIRST AMENDMENT TO AGREEMENT


         This First Amendment to the Agreement (the "Agreement") dated as of
June 21, 1999 (the "Agreement") is entered into by and between Tickets.com,
Inc., a Delaware corporation ("Tickets.com", formerly known as Advantix, Inc.)
and RBB Bank AG, a bank organized under the laws of Austria ("RBB").

                                   BACKGROUND

         The parties have determined that it is in their mutual best interest to
amend the Agreement in order to permit Tickets.com to purchase the 5,700 shares
of Series G Preferred Stock (the "Preferred Shares") of Lasergate Systems, Inc.
("Lasergate") held by RBB prior to any merger between Tickets.com and Lasergate
(the "Merger"). Accordingly, in consideration of the mutual covenants and
agreements set forth below, the parties agree as follows:

                                      TERMS

         1.       Purchase of Preferred Shares. Tickets.com agrees to purchase
                  all of the Preferred Shares within three business days (the
                  "Closing Date") of the execution of a definitive agreement and
                  plan of merger between Tickets.com, Advantix Acquisition Corp.
                  and Lasergate, in exchange for, at the election of RBB, (a)
                  170.081 shares of the common stock of Tickets.com for each
                  outstanding Preferred Share; or (b) $435.00 per each
                  outstanding Preferred Share, or a combination thereof. RBB
                  shall make its election, in writing, no later than 5:00 p.m.
                  Eastern time on June 21, 1999. If RBB elects to receive cash,
                  it shall include its wire transfer instructions with the
                  notice of its election.

         2.       Sale of Preferred Shares. On the Closing Date, RBB shall sell,
                  transfer, convey and deliver to Tickets.com, and Tickets.com
                  shall purchase and accept delivery of, the Preferred Shares.
                  RBB shall deliver to Tickets.com stock certificates
                  representing the Preferred Shares, together with appropriate
                  stock powers endorsed in blank.

         3.       Purchase Price. In exchange for this transfer of the Preferred
                  Shares by RBB, Tickets.com shall transfer, convey and deliver
                  to RBB cash or shares of the common stock of Tickets.com, or a
                  combination thereof, pursuant to the election made by RBB on
                  or before June 11, 1999 in accordance with Section 1 above. If
                  applicable, Tickets.com shall deliver to RBB a stock
                  certificate representing such shares of Tickets.com common
                  stock.

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         4.       Shares of Common Stock Held by RBB. The shares of common stock
                  of Lasergate held by RBB shall be purchased as part of the
                  Merger and not as part of this purchase transaction.

         5.       Conditions to Closing. The obligation of Tickets.com to
                  purchase RBB's Preferred Shares shall be subject to the
                  following conditions: (a) the execution of a definitive merger
                  agreement by Tickets.com and Lasergate; and (b) the
                  resignation of Jacqueline E. Soechtig ("JES") as an officer
                  and director of Lasergate and the receipt by Lasergate of a
                  release from JES (reasonably acceptable to Tickets.com).

         6.       Effect of the Agreement. All other provisions contained in the
                  Agreement and not amended by this Agreement, remain in full
                  force and effect.


         IN WITNESS WHEREOF, the undersigned have executed this Amendment as of
the date set forth above.

                                           TICKETS.COM, INC.


                                           By: /s/ John M. Markovich
                                              ---------------------------------
                                                John M. Markovich,
                                                Executive Vice President

                                           RBB BANK AG


                                           By: /s/ Herbert Strausz
                                              ---------------------------------
                                                Herbert Strausz, Manager
                                                U.S. Equities


