point your mouse to the frame you want to be reloaded. click on the RIGHT button and choose "reload".
You also can add the following php code to your page you want to be reloaded. With this code the page is never cached and you always get the newest content:
header ("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); // Date in the past
header ("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
// always modified
header ("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header ("Pragma: no-cache");
... source: php.net/manual/function.header.php