DHTML - Tell a friend (PHP + AJAX)

Need a 'tell a friend' php script using DHTML and potentially AJAX 1. Dhtml based (so when you click on the button, the tell a friend window pops up or slides across the window on top of the existing content) 2. Submit without reloading the page - so that when the user click on the submit button within the tell a friend form, the email is automatically sent out - without the page reloading (maybe ajax ? )