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: January 26, 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*
                                    --------------------------------------------

                                   *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

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