322985 coupon code script to landing

Hi, This is a verry simple project: I need a coupon code box where people can enter a coupon code and depend the code the people are redirected to a payment link. Like: Payment link 1: 27$ Payment link 2: 37$ When people enter the coupon code he are redirected the the link of payment where he can take advantage of his coupon code. I use clickbank so i have different payment link. Ready to fund escrow, Thanks