SID in header

I am using php to redirect my page. The problem that I am having is that I need it to carry the session variables with the redirect, and I am having trouble getting it to.

if ($_GET['cat_no']){
	$_SESSION['cat_no'] = $_GET['cat_no'];
	header('Location:http://www.idk.com/invoice.php?SID='.SID);
};

PHP:

I've looked at a few places in the net and that seems to be correct, but it doesn't work right.. any help is much appreciated.

 

Most probably a global variables problem. At the top of your code put something like this:

$SID = $_GET['SID'];

That's presuming before it redirects, the URL looks something like this:

http://www.domain.com/invoice.php?SID=something

Code (markup):

 

$session = session_name() . '=' . session_id();
header('Location: http://www.idk.com/invoice.php?' . $session);
exit();

PHP: