Configuring the "Thankyou" Page

This bit's easy. At the top of your thank you page (again, it has to be a PHP file), add the following code:

<?php
require_once("path/to/global/api/api.php");
$fields = ft_api_init_form_page();
ft_api_clear_form_sessions();
?>

Don't forget to update the path to the API file, just like with your other pages.