EX-99.1 4 dex991.txt AGREEMENT ------------------------ -------------------------- CUSIP No. 68554M108 13G Page 22 of 22 Pages --------- ------------------------ -------------------------- Exhibit 99.1 ------------ AGREEMENT Pursuant to Rule 13d-1(k)(1) promulgated pursuant to the Securities Exchange Act of 1934, as amended, the undersigned agree that the attached Schedule 13G is being filed on behalf of each of the undersigned. February 14, 2002 VENROCK ASSOCIATES By: /s/ Anthony B. Evnin ----------------------------- Anthony B. Evnin General Partner February 14, 2002 VENROCK ASSOCIATES II, L.P. By: /s/ Anthony B. Evnin ----------------------------- Anthony B. Evnin General Partner February 14, 2002 GENERAL PARTNERS * ------------------------------------ Michael C. Brooks * ------------------------------------ Joseph E. Casey * ------------------------------------ Eric S. Copeland * ------------------------------------ Anthony B. Evnin * ------------------------------------ Thomas R. Frederick * ------------------------------------ David R. Hathaway * ------------------------------------ Patrick F. Latterell /s/ Bryan E. Roberts ------------------------------------ Bryan E. Roberts * ------------------------------------ Ray A. Rothrock * ------------------------------------ Kimberley A. Rummelsburg * ------------------------------------ Anthony Sun * ------------------------------------ Michael F. Tyrrell * By: /s/ Anthony B. Evnin ----------------------------- Anthony B. Evnin Attorney-in-Fact