Redirecting users after login

[passagewds]

I want to make a session variable of the requested page so that when a person tries to go to a protected page and isn't logged in, they are sent to the login page. After they login then they are redirected back to the page they wanted.

[passagewds]

OK, I have figured out that the getenv("SCRIPT_NAME") works for this but....

I tried to load it in a session variable to pass to the login page but the login page doesn't see the session variable.

The regular page top looks like this....

<?php
session_start();
if (@$auth != "yes")
{
session_register('RegPage');
$getnv = getenv("SCRIPT_NAME");
$_SESSION['ReqPage'] = $getnv;
header("Location: ../../login_form.php");
exit();
}
?>

The login page redirect for a successful login looks like this

header("Location: $RegPage");

why doesn't it work?