Exhibit 23 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our report included in this Form 10-K/A, into the Company's previously filed Registration Statements (File No. 333-50259; File No. 333-94439 and File No. 333-89683). /s/ ARTHUR ANDERSEN LLP - ------------------------- Arthur Andersen LLP San Antonio, Texas April 13, 2000