The PDT-System is a complete back-end system for handling paypal transactions. This script is used for handling downloads after the transaction without using the fancy costly help from paypal. In other words, it is a complete stand-alone system that controls the post transaction data. The PDT-System has strict buyer guidelines. After every purchase the download can only be accessed 3 times before being told, “Sorry, you have reached your maximum download limit.” The user downloading has to perform the download on the same machine, and in the same browser, that the purchase was made from. This prevents the buyer from sharing the download link with another user.  

 There is a specific format, which is why the PDT-System consists of four files as opposed to one. The download button cannot be produced without a prior paypal transaction. The systems 4 files and method is explained better in the diagram below.