Authenticated User Session Control On Non-VB Page

[LifesGreatestGift]

I am currently running an image hosting script and want to limit it to my members only.

The image hosting script is located at

/home/jesse123/public_html/TW7S.com/images/

and my forum is

/home/jesse123/public_html/TheWindows7Site.com/forum/

Here is the code I have in the image hosting scripts index page:

PHP Code:

<?

$url = "http://www.thewindows7site.com/forum/";


$curdir = getcwd ();
chdir('/home/jesse123/public_html/thewindows7site.com/forum');
require_once('/home/jesse123/public_html/thewindows7site.com/forum/global.php');


if ($bbuserinfo['userid'] =0) {


?>
<script type="text/javascript" language="JavaScript">
<!--
alert("You Must Register/Login To The Forum\n\To Use This Feature. -Administration Team");

   window.location="<?php echo $url; ?>";
// -->
</script>

<?

}

else

{
   echo"Thanks For Logging In, <b>$username</b>";
}

chdir ($curdir);

// IMAGE HOSTING SCRIPT .........

What am I doing wrong?