"add to cart" buttons

[MattMorganDesigns]

I am building a site ( http://www.180decals.com/catalog ). I am having troubles applying the php code for my "add to cart" buttons. I have successfully linked to the shopping cart page, but it isn't adding the item to the cart. What code am I missing to add the item to the cart.

 

Any ideas will help.

Thanks

 

Matt Morgan Designs

http://www.mattmorgandesigns.com