Exhibit 99.1 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 ---------------------------------------------- In connection with the Quarterly Report of 榴莲视频 (the "Corporation") on Form 10-Q for the period ending March 31, 2003 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Thomas J. Usher, Chairman of the Board of Directors and Chief Executive Officer of the Corporation, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that: (1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and (2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Corporation. By /s/ Thomas J. Usher ------------------- Thomas J. Usher Chairman of the Board of Directors and Chief Executive Officer May 12, 2003 A signed original of this written statement required by Section 906 has been provided to 榴莲视频 and will be retained by United States Steel Corporation and furnished to the Securities and Exchange Commission or its staff upon request.