validation joinform jquery json

i need a join form written for a php website, using jquery and json that validates the user names serverside (php), a password match, checkbox, email verification and a captcha before the user submits the form, also include hints. It will need to be cross browser compatible. I have an example of a sliding jquery form that I would like to use. When the user clicks on a join link or button it will open a lightbox and have the sliding form within it. I will provide the finer details later. Sliding example [login to view URL]