Create custom 404 error documents with PHP, Force no-cache using PHP

Custom Error Document 404 with PHP
http://www.devarticles.com/c/a/Apache/Custom-Error-404-Documents-with-PHP/

PHP: Force no-cache (using PHP header)
http://in.php.net/header

<?php
header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past
?>