197462 Custom PHP script - Coupons

Alright, I need a custom PHP script. Basically a user comes to our site and can submit a coupon code. Please see mock up at: [login to view URL] This is what I want above (mock up). I explained more in detail on the mock up. Needs to have the same function as the live version below (ajax, javascript, ect.) A live version can be seen at: [login to view URL] (Their site is really complex, I just want one feature, the coupon part) Thanks and happy bidding. Shouldn't take longer than a day.