EXHIBIT 23.1

                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS

As independent public accountants, we hereby consent to the incorporation of our
reports included in this Form 10-K, into the Company's previously filed
Registration Statements on Form S-8 File No. 333-2914, Form S-8 File No.
333-71340, Form S-3 File No. 333-57281, and on Form S-3 File No. 333-71342.

                                          ARTHUR ANDERSEN LLP

Dallas, Texas
April 1, 2002