<PAGE>

                                                                   EXHIBIT 10.19

                         AMENDMENT TO PURCHASE AGREEMENT

         This Amendment to Purchase Agreement (this "Amendment") is made this
16th day of June, 2004, among Douglas P. Wilson, as Special Master under the
Stipulation and Order and as Seller (the "Seller"), Bernardo Property Advisors,
Inc., a California corporation ("Buyer"), GAL-Brisbane, L.P., a California
limited partnership ("Owner"), Brisbane Tech LLC, a Delaware limited liability
company ("Brisbane Tech"), and Roger C. Stuhlmuller, an individual
(collectively, the "Parties").

                                    Recitals

         WHEREAS, the Parties entered into that certain Purchase Agreement dated
as of May 24, 2004 (the "Purchase Agreement"); and

         WHEREAS, the Parties desire to amend the Purchase Agreement to allow
Buyer additional time to complete its due diligence as contemplated by the
Purchase Agreement.

                                    Agreement

         NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Parties hereby agree as
follows:

         1.       Recital A(c) of the Purchase Agreement shall hereby be
replaced in its entirety with the following: "Due Diligence Period: Begins on
the Effective Date and ends at 5:00 p.m., Los Angeles, California local time, on
June 18, 2004."

         2.       The following is hereby added to the Purchase Agreement as new
subsection 1.2(h): "As consideration for extending the expiration date of the
Due Diligence Period to June 18, 2004, Buyer shall pay Two Thousand Five Hundred
Dollars ($2,500) to Lender, on or before June 28, 2004, as reimbursement for
attorneys' fees and other costs incurred by Lender related to the granting of
such extension. Buyer's failure to timely make such payment to Lender shall
constitute a breach of this Agreement."

         3.       This Amendment may be executed in any number of counterparts,
and upon execution by the Parties, each executed counterpart shall have the same
force and effect as an original instrument and as if the Parties had signed the
same instrument.

         4.       Except as stated herein, the Purchase Agreement shall remain
unmodified and in full force and effect.

                [REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK]

<PAGE>

         IN WITNESS WHEREOF, the Parties have executed this Amendment as of the
date and year first written above.

                                    SELLER:

                                    /s/ DOUGLAS P. WILSON
                                    --------------------------------------------
                                    DOUGLAS P. WILSON, Special Master

                                    BUYER:

                                    BERNARDO PROPERTY ADVISORS, INC.,
                                    a California corporation


                                    By: /s/ GARY A. KREITZER
                                        ----------------------------------------
                                    Name: Gary A. Kreitzer
                                          --------------------------------------
                                    Its: Executive V.P.
                                         ---------------------------------------

                                    OWNER:

                                    GAL-BRISBANE, L.P.,
                                    a California limited partnership

                                    By: Brisbane Tech LLC,
                                        a Delaware limited liability company

                                        By: Stuhlmuller Real Estate, LLC,
                                            a Delaware limited liability company

                                            By: /s/ ROGER C. STUHLMULLER
                                                --------------------------------
                                                Roger C. Stuhlmuller,
                                                Manager

                                    BRISBANE TECH:

                                    BRISBANE TECH LLC,
                                    a Delaware limited liability company

                                    By: Stuhlmuller Real Estate, LLC,
                                        a Delaware limited liability company

                                        By: /s/ ROGER C. STUHLMULLER
                                            ------------------------------------
                                            Roger C. Stuhlmuller, Manager

<PAGE>

                                    ROGER C. STUHLMULLER:

                                    /s/ ROGER C. STUHLMULLER
                                    --------------------------------------------
                                    ROGER C. STUHLMULLER, an individual

                                    APPROVED BY:

                                    Credit Suisse First Boston Mortgage Capital
                                    LLC, a Delaware limited liability company

                                    By: /s/ STEPHEN YANKAUER
                                        ----------------------------------------
                                    Name: Stephen Yankauer
                                          --------------------------------------
                                    Its: Vice President
                                         ---------------------------------------

         Chicago Title Company acknowledges receipt of a copy of this Amendment
executed by Seller, Buyer, Owner, Brisbane Tech and Roger C. Stuhlmuller.

         Dated: June 28, 2004       CHICAGO TITLE COMPANY

                                    By: /s/ MARLEY HARRILL
                                        ----------------------------------------
                                    Name: Marley Harrill
                                          --------------------------------------
                                    Its: Assistant Vice President
                                         ---------------------------------------