How do I prevent Web browsers caching a page using PHP?

<?php
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Pragma: no-cache");
?>

We can go one step further, using the Cache-Control header that’s supported by HTTP 1.1 capable browsers:

<?php
header("Expires: Mon, 26 Jul 2007 05:00:00 GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", FALSE);
header("Pragma: no-cache");
?>