<br/>X-cart has an old login mechanism where users have to create a username.<br/><br/><br/>If a user doesn't remember their username, I want people to be able to login to see their previous orders and whatnot by using their email address or logging in using their facebook account.<br/><br/><br/>I assume facebook authentication will pass the user's email address back to x-cart.<br/><br/><br/>As long as the user has the same email address in the x-cart database as they used with facebook they should be able to login - correct me if I'm wrong - I don't know how facebook's API works.<br/><br/><br/>Must support 'anonymous' users: when a customer checkouts without supplying a username and password, an anonymous user account is created.<br/><br/><br/>x-cart code must be altered to allow anonymous users to login.<br/><br/><br/>code and documentation must be included.<br/><br/><br/>Instructions for installing this functionality must include:<br/><br/>-step by step installation steps to apply to other x-cart sites (this will be tested on a test site and then moved to live).<br/><br/>-x-cart files that need to be changed, including code edits (before and after)<br/><br/><br/>x-cart is a PHP shopping cart.<br/><br/><br/>X-cart experience is extremely helpful.<br/><br/><br/>Bonus for including google account authentication<br/><br/><br/><br/>