HTTP:
<META HTTP-EQUIV="pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache, must-revalidate">
<META HTTP-EQUIV="expires" CONTENT="Wed, 26 Feb 1997 08:21:57 GMT">
<META HTTP-EQUIV="expires" CONTENT="0">
ASP
response.expires=0
response.addHeader("pragma","no-cache")
response.addHeader("Cache-Control","no-cache, must-revalidate")
PHP
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Cache-Control: no-cache, must-revalidate");
header("Pragma: no-cache");
JSP:
response.addHeader("Cache-Control", "no-cache");
response.addHeader("Expires", "Thu, 01 Jan 1970 00:00:01 GMT");