I Need a Rotator Script

Hello I Need a Rotator Script. I have a duplicated website were member promote an affiliate link, So we need these affiliate link to changes (rotate) pulling the data from database, members need to enter this data from they control panel (backoffice), we will be enter our members affiliate link to help the on traffic (more sales for them) if they make money we make too, this will be a team work! Example: I enter 4 usernames (data to rotate) in my backoffice. 1: memberaffiliatelink1, 2: memberaffiliatelink2, 3: memberaffiliatelink3 4: memberaffiliatelink4 This is my regular afiliate link <a href="[login to view URL]; ?>" when I active the rotator my username will change (rotate) every time someone visit my website and click on the buy button this will send them to [login to view URL], then the next visitor when they click the buy button this will send them to [login to view URL] and the next [login to view URL] and [login to view URL] and now will start over! we need this as an option, member can enable or disable the rotator. Our website is in Spanish language and we are a team. we work together. we promote English products to Spanish community, so we design a website where we Explain the product in Spanish, and customer buy the product.