HTML
<META HTTP-EQUIV="pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache, must-revalidate">
<META HTTP-EQUIV="expires" CONTENT="Mon, 23 Jan 1978 20:52:30 GMT">

ASP

<%
Response.Expires = -1
Response.ExpiresAbsolute = Now() - 1
Response.cachecontrol = "no-cache"
%>

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Cache-Control: no-cache, must-revalidate");
header("Pragma: no-cache");

response.setHeader("Pragma","No-Cache");
response.setHeader("Cache-Control","No-Cache");
response.setDateHeader("Expires", 0);