I do have IDC, an e-product download cart which allowes to sell products and after payment it allows downloading them immediatelly. Upon placement of orders it stores in the database the order details (like nr, products, date, amount, etc). After payment (through PayPal) it also updates the database with all the customer details (as it recieves it from PayPal). HAve a look at http://www.dbtechnosystems.com./idc.php

However, this is apaid for cart.

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