<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>a2143253zex-99_1.txt
<DESCRIPTION>EXHIBIT 99.1
<TEXT>
<Page>


                                    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: September 10, 2004

                      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

</TEXT>
</DOCUMENT>