每次都要搜索，记不往，整理如下：

php
设置一个过期日期
header(“Expires: Mon, 26 Jul 1979 05:00:00 GMT”);
或告诉浏览器不要缓存
header(“Cache-Control: no-store, no-cache, must-revalidate”);

asp
<%
Response.Expires = 0
Response.ExpiresAbsolute = Now() - 1
Response.AddHeader "pragma", "no-cache"
Response.AddHeader "cache-control", "private, no-cache, must-revalidate"
%>

html
<meta http-equiv="Expires" content="Tue, 26-Jul-1979 05:00:00 GMT">