Sorry about that, it looks like you got the original code from my post, I had to edit that code because of the syntax error, the code in that post was updated but here it is again, you should use this for the set session value code:
<?php
if (!session_id()) session_start();
if(isset($_POST['UPS_Service']) && $_POST['UPS_Service'] != "") {
$_SESSION["Shipping"] = "".$_POST['UPS_Service'] ."";
}
?>