EXHIBIT A JOINT FILING UNDERTAKING The undersigned, being duly authorized thereunto, hereby execute this agreement as an exhibit to the Schedule 13D to evidence the agreement of the below-named parties, in accordance with rules promulgated pursuant to...

CUSIP no. 382410-18-8                                       Page 13 of 13 Pages


                                    EXHIBIT A

                            JOINT FILING UNDERTAKING


     The undersigned, being duly authorized thereunto, hereby execute this
agreement as an exhibit to the Schedule 13D to evidence the agreement of the
below-named parties, in accordance with rules promulgated pursuant to the
Securities Exchange Act of 1934, to file this Schedule 13D jointly on behalf of
each of such parties.

DATED: October 4, 1999

XXXXXXXXX & XXXXX GUARANTY FINANCE, LLC

By: Xxxxxx X. Xxxxxxxx
    -----------------------------------

Its: Chief Executive Officer



XXXXXXXXX & XXXXX GROUP

By: Xxxxxx X. Xxxx XXX
    -----------------------------------

Its:  Chairman and Chief Executive Officer



XXXXXXXXX & XXXXX CALIFORNIA

By: Xxxxxx X. Xxxx XXX
    ----------------------------------

Its:  Chairman and Chief Executive Officer


Xxxxxx X. Xxxx XXX
---------------------------------------------
Xxxxxx X. Xxxx XXX


Xxxxxx X. Xxxxxxxx
---------------------------------------------
Xxxxxx X. Xxxxxxxx