Want a free T-shirt?

http://alphageeknation.com/LPR.asp?L=28

only 2 sizes available, large and extra large..

It's asking for a code. I've filled everything out. Any idea what they want?

On the right hand side it asks for you info. I'm haven't seen a place for a code. I filled it out and received a confirmation e-mail stating my free t-shirt and free magazine would be sent 4-6 weeks.