Exhibit 10(l)

Borrower and Bank hereby agree that the Maturity Date of the Note is hereby extended until July 31, 2010, at which time all outstanding principal, together with all accrued interest which has not been paid, shall be due and payable in full. All references in the Note or the other Loan Documents to the “Maturity Date” shall hereafter be modified to reflect July 31, 2010, as the “Maturity Date”, unless the indebtedness evidenced by the Note is otherwise accelerated following a Default or the occurrence of an Event of Default. The Liens (as defined below) are hereby extended until the Note as extended hereby, and all other obligations and indebtedness secured by the Loan Documents are fully paid and satisfied.

Borrower and Bank hereby acknowledge and agree that, from and after the date hereof, the definition of the term “Revolving Credit Maturity Date”, as set forth in Section 1.1 of the Credit Agreement entitled “Defined Terms”, is hereby modified and replaced in its entirety with the following:

Borrower and Bank hereby acknowledge and agree that, from and after the date hereof, the definition of the term “Applicable Margin”, as set forth in the Note, is hereby modified and replaced in its entirety with the following:

Borrower is responsible for all costs incurred by Bank, including without limit reasonable attorneys’ fees (whether inside or outside counsel is used), with regard to the preparation and execution of this Fourth Amendment.

The execution of this Fourth Amendment shall not be deemed to be a waiver of any Default or the occurrence of an Event of Default.

All the terms used in this Fourth Amendment which are defined in the Note and/or Credit Agreement shall have the same meaning as used in the Note and/or Credit Agreement, unless otherwise defined in this Fourth Amendment.

Borrower waives, discharges, and forever releases Bank, Bank’s employees, officers, directors, attorneys, stockholders, and their successors and assigns, from and of any and all claims, causes of action, allegations or assertions that Borrower has or may have had at any time up through and including the date of this Fourth Amendment, against any or all of the foregoing, regardless of whether any such claims, causes of action, allegations or assertions are known to Borrower or whether any such claims, causes of action, allegations or assertions arose as a result of Bank’s actions or omissions in connection with the Note or Credit Agreement, or any amendments, extensions or modifications thereof, or Bank’s administration of the Indebtedness or otherwise, INCLUDING ANY CLAIMS, CAUSES OF ACTION, ALLEGATIONS OR ASSERTIONS RESULTING FROM BANK’S OWN NEGLIGENCE, except and to the extent (but only to the extent) caused by Bank’s gross negligence or willful misconduct.

All Liens which secure or purport to secure the Indebtedness, including the indebtedness evidenced by the Note, are hereby ratified, confirmed, brought forward, renewed, extended and rearranged as security for the Indebtedness. The term “Lien” shall mean any valid and enforceable interest in any property, whether real, personal or mixed, securing an indebtedness, obligation or liability owed to or claimed by any person other than the owner of such property, whether such indebtedness is based on the common law or any statute or contract and including, but not limited to, a security interest, pledge, mortgage, assignment, conditional sale, trust receipt, lease, consignment or bailment for security purposes.

This Fourth Amendment is not an agreement to any further or other amendment of the Note or Credit Agreement.

Borrower expressly acknowledges and agrees that except as expressly amended in this Fourth Amendment, the Note and Credit Agreement, as amended, remain in full force and effect and are ratified, confirmed and restated. This Fourth Amendment shall neither extinguish nor constitute a novation of the Note or indebtedness evidenced thereby.

THIS FOURTH AMENDMENT AND THE OTHER “LOAN AGREEMENTS” (AS DEFINED IN SECTION 26.02(A)(2) OF THE TEXAS BUSINESS & COMMERCE CODE, AS AMENDED) REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES, AND THIS AGREEMENT AND THE OTHER WRITTEN LOAN AGREEMENTS MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS BETWEEN THE PARTIES. THERE ARE NO UNWRITTEN AGREEMENTS BETWEEN THE PARTIES.