Much as it pains me to agree with Artie505 (I'm kidding, of course) I think he is on the right track. I don't know if the laptop you are working with has the Airport card soldered on the logic board or if it is a separate component, but in either case if it is a hardware failure it would probably be cheaper to buy a newer computer than an airport card or new logic board for the existing machine.
"All you've got to do is own up to your ignorance honestly, and you'll find people who are eager to fill your head with information" --Walt Disney
(I'm kidding, of course) I think he is on the right track. I don't know if the laptop you are working with has the Airport card soldered on the logic board or if it is a separate component, but in either case if it is a hardware failure it would probably be cheaper to buy a newer computer than an airport card or new logic board for the existing machine. 
