Hi, I'm looking to use the web store, I know it's not been developed to be too detailed, but I was hoping that I could alter the form that gathers the buyers info? 

Basically I want to add a field with a registration number that the buyer knows.

My other question is around quantity. I know I can set a product quantity, but this doesn't seem to take effect. I had hoped that the product would become unavailable when the product quantity had been exceeded, but this doesn't seem to be the case.