PayPal simple integration with classic ASP

We need to integrate PayPal into our classic ASP (not ASP.NET) website to accept PayPal payment for a single purchase item, without utilizing a shopping cart. Payment is available only for registered users (every user has a unique userID). Also, the purchase item has its own unique itemID. 1. On click on a "Pay with Credit Card” button, user needs to be redirected to a PayPal payment page (including userID and itemID) where information needs to be displayed for user to complete the payment. 3. On successful payment, user needs to be redirected back to our website (success URL), where we need to receive posted information from PayPal (and get back an userID and itemID, too) to update our database and send a confirmation email to the user. We don’t need a code to update database, or to sent confirmation email code… We only need a code which will make a PayPal payment for userID / itemID, and receive successfull payment data from PayPal. 4. If user cancels the payment (or payment wasn’t successfull), user needs to be redirected back to our website (error URL), where we need to receive posted information (and get back an userID and itemID) to update the database and send a an alert email to an user. Please be carefull: we need a classic ASP and not ASP.NET code.