Payment system for an online store of practical work?
The University was given a practical assignment to write an online store. So it is necessary to write your own payment system (simple. that would withdraw money from a virtual balance and transferred to a virtual balance store, checked if there is enough money from user account, check the user's details correctly in the payment.)
Online store I have time to make before delivery, but payment system is not, in this regard, I want to ask a question, whether there is at someone such payment system done in PHP or where to download?