Exhibit A AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13G In accordance with Rule 13d-1(k)(1)(iii) promulgated by the Securities and Exchange Commission pursuant to Section 13 of the Securities and Exchange Act of 1934, as amended, the...

                                                                       Exhibit A

              AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13G

     In accordance with Rule 13d-1(k)(1)(iii) promulgated by the Securities and
Exchange Commission pursuant to Section 13 of the Securities and Exchange Act of
1934, as amended, the undersigned hereby agree as follows:

     (i) Each of them is individually eligible to use the Schedule 13G to which
this Exhibit is attached, and such Schedule 13G is filed on behalf of each of
them; and

     (ii) each of them is responsible for the timely filing of such Schedule 13G
and any amendments thereto, and for the completeness and accuracy of the
information concerning such person contained therein; but none of them is
responsible for the completeness or accuracy of the information concerning the
other persons making the filing, unless such person knows or has reason to
believe that such information is inaccurate.

Date: February 8, 2002

                                       ▇▇▇▇ CAPITAL FUND VI, L.P.

                                       By: ▇▇▇▇ Capital Partners VI, L.P.,
                                           its General Partner

                                       By: ▇▇▇▇ Capital Investors, LLC,
                                           its General Partner

                                       By: /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           ------------------------------------
                                           Name:  ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           Title: Attorney-in-Fact


                                       ▇▇▇▇ CAPITAL PARTNERS VI, L.P.

                                       By: ▇▇▇▇ Capital Investors, LLC,
                                           its General Partner

                                       By: /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           ------------------------------------
                                           Name:  ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           Title: Attorney-in-Fact


                                       ▇▇▇▇ CAPITAL INVESTORS, LLC

                                       By: /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           ------------------------------------
                                           Name:  ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           Title: Attorney-in-Fact



                                       BCIP ASSOCIATES II
                                       BCIP TRUST ASSOCIATES II
                                       BCIP ASSOCIATES II-B
                                       BCIP TRUST ASSOCIATES II-B
                                       BCIP ASSOCIATES II-C

                                       By: ▇▇▇▇ Capital Investors, LLC,
                                           their Managing General Partner

                                       By: /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           ------------------------------------
                                           Name:  ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           Title: Attorney-in-Fact


                                       PEP INVESTMENTS PTY LIMITED

                                       By: ▇▇▇▇ Capital Investors, LLC
                                           its Attorney-in-Fact

                                       By: /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           ------------------------------------
                                           Name:  ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                           Title: Attorney-in-Fact








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