Check for SSL

This is not working - can't figure out why.
If I try to change the header, I get an error.
If I try to echo the server variables, I get an error.

<?php
if($_SERVER["HTTPS"] != "on" || $_SERVER["SERVER_PORT"] != "443") {
?>
    <script type="text/javascript">
      document.forms[0].action="https://www.xxxxxxxx.com/order.php";
      document.forms[0].submit();
    </script>
<?php
}
?>

and I tried this - no alert!

<script type="text/javascript">
var sValue = <?php $_SERVER["HTTPS"] ?>;
alert(sValue);
</script>  

It's out on 123ehost, so I can't set or control a lot of things.