AJAX web application II

I need a freelancer with very good skills in Javascipt, DHTML and cross-browser development in order to develop a graphical API to an application, basing the work on an AJAX Platform and an already defined webdesign and XML structure. NOTE: I need someone with at least 3 years of experience on this type of technology and some examples of work done. The budget for the initial project is around $500. Then it will probably need many upgrades.