simple page not found 404 script - PHP

Dear All, I have made a simple php script that will show an 404.php error page when an item is removed. You can see the page here: http://arubaguide.org/arubaguide/categories.php?catcode=art But some how this is not working. It is displaying the 404 page and the normal page. <?php /* function to get an external file into a vatiable */ function get_include_contents($filename) { if (is_file($filename)) { ob_start(); include $filename; $contents = ob_get_contents(); ob_end_clean(); return $contents; } return false; } /* configuration file */ $errormsg = get_include_contents('404.php'); $pagename = $_GET['page']; /* end configuration file */ if(file_exists("$pagename")) { include "$pagename"; } else { echo "$errormsg"; } ?> is the $pagename not enough for this script? Let me know.. Dwayne