<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>a2175863zex-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.

Dated: February 8, 2007


                      CITIGROUP INSTITUTIONAL TRUST COMPANY
                      As Trustee for Eternity Four Trust


                      By: /s/ Megan McCafferty
                         --------------------------------------------
                         Name:  Megan McCafferty
                         Title: Vice President


                      CITIGROUP INC.


                      By: /s/ Riqueza V. Feaster
                         --------------------------------------------
                         Name:  Riqueza V. Feaster
                         Title: Assistant Secretary


</TEXT>
</DOCUMENT>