JOINT FILING AGREEMENT

                                                                       EXHIBIT 1

                             JOINT FILING AGREEMENT

     The undersigned hereby agree to the joint filing of the Schedule 13G to
which this Agreement is attached.

               Dated: August 9, 2005

                              ARTISAN INVESTMENT CORPORATION
                              for itself and as general partner of
                              ARTISAN PARTNERS LIMITED PARTNERSHIP


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

                              XXXXXX X. XXXXXXX


                              Xxxxxx X. Xxxxxxx*
                              --------------------------------------------------

                              XXXXXXX XXXXXX XXXXXXX


                              Xxxxxxx Xxxxxx Xxxxxxx*
                              --------------------------------------------------


                              ARTISAN FUNDS, INC.


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


                              *By: /s/ Xxxxxxxx X. Xxxxxx
                                   ---------------------------------------------
                                   Xxxxxxxx X. Xxxxxx
                                   Chief Financial Officer of Artisan Investment
                                   Corporation
                                   Attorney-in-Fact for Xxxxxx X. Xxxxxxx
                                   Attorney-in-Fact for Xxxxxxx Xxxxxx Xxxxxxx
                                   Chief Financial Officer and Treasurer
                                   of Artisan Funds, Inc.

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