PHP No-cache headers

These php headers wil prevent client side caching of your php output:

<?php
	//no  cache headers 
	header("Expires: Mon, 26 Jul 1990 05:00:00 GMT");
	header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
	header("Cache-Control: no-store, no-cache, must-revalidate");
	header("Cache-Control: post-check=0, pre-check=0", false);
	header("Pragma: no-cache");
?>