<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>3
<FILENAME>a2072974zex-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: March 8, 2002


                      SMITH BARNEY FUND MANAGEMENT LLC


                      By: /s/ Christina T. Sydor
                         --------------------------------------------
                         Name:  Christina T. Sydor
                         Title:  Secretary


                      SALOMON SMITH BARNEY HOLDINGS INC.


                      By: /s/ Joseph B. Wollard
                         --------------------------------------------
                         Name:  Joseph B. Wollard
                         Title:  Assistant Secretary


                      CITIGROUP INC.


                      By: /s/ Joseph B. Wollard
                         --------------------------------------------
                         Name:  Joseph B. Wollard
                         Title: Assistant Secretary


</TEXT>
</DOCUMENT>