Hello, I´m making a video manual, but i don´t want to be cached in the client machine. I make a script like this: <?php header("Expires: Mon, 26 Jul 1997 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"); readfile($video_name); ?> With Internet explorer the script works fine. But Firefox have two types of cache: Memory cache and disk cache. With firefox disk cache, the script works fine, because don´t appears in the disk cache, but i have problems with the Memory cache. How can i avoid to appears in the firefox memory cache?