<?php if ($_SERVER["HTTP_IF_MODIFIED_SINCE"]) { header("HTTP/1.0 304 Not Modified"); exit; } $max_age = 12 * 31 * 24 * 60 * 60; //one year $expires = gmdate(DATE_RFC1123, time() + $max_age); $last_modified = gmdate(DATE_RFC1123, time() - $max_age); header("Cache-Control: public, max-age=" . 5*$max_age); header("Cache-control: max-age=0"); header("Expires: " . $expires); header("Content-Type: text/html"); header("Last-Modified: " . $last_modified); echo(rand()); ?>