SPECIAL POWER OF ATTORNEY
Known all men by these presents, that I, Dr. Michael R. Ferrari, hereby
constitute and appoint Michael A. Carter, my true and lawful attorney-in-fact
and agent, with full power of substitution and resubstitution, for me and in
my name, place and stead, in any and all capacities, to sign any or all SEC
Forms 4 and 5, granting unto said attorney-in-fact and agent full power and
authority to do and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as I might or could do in person, hereby ratifying and confirming all
that said attorney-in-fact and agent, or his substitute or substitutes, may
lawfully do or cause to be done by virtue hereof.

I further hereby revoke and rescind all prior attorney-in-fact and agent
appointments made by me with respect to the above subject matter.

IN WITNESS WHEREOF, I have hereunto set my hand this __12___ day of
December, 2005.
                 /s/ Michael R. Ferrari
		_____________________________________
		Michael R. Ferrari

STATE OF TEXAS

COUNTY OF TARRANT

Before me, the undersigned authority, on this day personally appeared
Michael R. Ferrari, known to me to be the person whose name is
subscribed to the foregoing instrument and acknowledged to me that he
executed the same for the purposes and consideration therein expressed.

Given under my hand and seal of office this __12___ day of December, 2005.

(seal)					/s/Angela Littner-Garcia
					__________________________
				Notary Public in and for the State of Texas
My commission expires:January 14, 2008