Question

I'm designing a site for sister in law who is selling gift baskets, I'm 
using Buy me buttons generate on the paypal site to add items to the 
shopping cart. (this is due to web page design )

Anyway, what she now wants to do is to have a custom basket item, in which 
the buyer/customer selects a certain number of items from a list lets say 
via a check box. How can I do this?

Thanks in advance for any help