在product.tpl中集成ajax选项检查打开购物车

I want to put ajax check script in product.tpl(catalog), it should take the entered text box value and should check in database, if not exists immediately it should give the error message there itself. I have ajax script for that, but not able to integrate as i cannot take textbox name, which is generated from backend.I want to put ajax check script in product.tpl(