After opening a lightbox with thickbox: see http://jquery.com/demo/thickbox/
You can close the lightbox and have an href link open a url in the parent window:
Register for an Infinite Connection account.
Also to have a form and click submit but close the lightbox and have the form submit to the parent page use this code.
<?php
$output .= "
?>
this took me an hour or two to figure out, so you're welcome :)