ADD 'coupon' feature to osCommerce Cart

I have a cart running at this url: [login to view URL] I need to be able to have a coupon created from an admin page, the coupon will need an ID, and a percentage to deduct from the order. Not including shipping. It's a pretty standard coupon.. for now, one coupon at 20% and a page where I can change it, or create new ones is all I need. The admin page for the coupon does NOT need to be built into the current admin panel for osCommerce, it can be a stand-a-lone [login to view URL] page in the admin directory. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Windows 2000, php. You will be given a Terminal Services login, administrator account on the computer. The server has 768/768 DSL so unless you are on the other side of the world, you should be able to work pretty quickly through Terminal Services.