Fix Oscommerce Php Problems

I am the webmaster of 22 oscommerce stores and we have a variety of small fixes that need to be done throughout the websites. Such as selecting a shipping option at [login to view URL] and minor other checkout problems where credit cards should be processed automaticly. We basicly want someone to go through the 22 stores and look for issues that would cause checkout not to be completed such as creating an account, selecting shipping options, or automaticly processing credit cards. Our main store is [login to view URL] but we have many simular substores and we need to have checked for errors and fixed. Estimated work should be a few days.