Ecart Purchase adds credits
I've got a project that I'm using eCart for. The product to be sold is 20 credits. My issue is when the customer completes a transaction and pays via paypal I want to add 20 credits to their account. I'm using php, mysql, dreamweaver CS3 on a MacPro Intel. I have the latest version of eCart. My database fields are:
ID = consid -- this is the id for the customer
credits -- integer field -- this is the field that I want to add 20 credits to -- the default is 0
I want to add the credits automatically after they leave the paypal site.