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                                    EXHIBIT 1
                                    ---------

                  AGREEMENT AS TO JOINT FILING OF SCHEDULE 13G
                  --------------------------------------------

Each of the undersigned hereby affirms that it is individually eligible to use
Schedule 13G, and agrees that this Schedule 13G is filed on its behalf.

Date: August 9, 2004

                      SMITH BARNEY FUND MANAGEMENT LLC



                      By: /s/ Thomas C. Mandia
                         --------------------------------------------
                         Name:  Thomas C. Mandia
                         Title:  Secretary



                      CITIGROUP GLOBAL MARKETS HOLDINGS INC.



                      By: /s/ Serena D. Moe
                         --------------------------------------------
                         Name:  Serena D. Moe
                         Title:  Assistant Secretary



                      CITIGROUP INC.



                      By: /s/ Serena D. Moe
                         --------------------------------------------
                         Name:  Serena D. Moe
                         Title: Assistant Secretary



