thanks, and yes my app/shopping cart is database driven but i don't see how this has to do with above code fragment.

I'm using "Pro Integration" as supposed to "Standard Integration" - I *think* [Am I right?] it allows Direct Payment - i.e. accept credit card without leaving my site.

Now, with Pro Integration {whether "Direct Payment API" or "Express"} you'd need to send request to Paypal and receive response from Paypal. I suppose you're NOT going to navigate away from your site [Am I right?], which is why AJAX comes in. Send a request via POST, then AJAX handler will invoke "handleResponse" (then parse response query string to stripped out Paypal Name-value pairs response code). Now, this should be same whether your cart items are hard coded on your webpage or dynamically rendered as driven by database.