I apologize, i gave you the wrong code chunk for authorize.net, the code to add is:
<?php
if(!session_id()) session_start();
echo "<p>Auth Net: <br />";
echo "Full Request: ".(isset($_SESSION['WAAuthNet_postedValues'])?htmlentities($_SESSION['WAAuthNet_postedValues']):"n/a")."<br />";
echo "Full Response: ".(isset($_SESSION['WAAuthNet'])?htmlentities($_SESSION['WAAuthNet']):"n/a")."<br /></p>";
?>