build backend for ecommerce site

We have front end ready for ecommerce website. All the html/css files are ready and we just need to build the backend with basic features for ecommerce website at this stage. In future, client want additional features! There will be flash intro and we will provide you all the fla and concerned files. So your job will be to build the backend. If we are happy similar jobs will follow. You need to build in php/mysql and use AJAX where applicable. We are on tight budget.