Try this:
<META HTTP-EQUIV="Cache-Control" CONTENT="max-age=0">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache">
<META http-equiv="expires" content="0">
<META HTTP-EQUIV="Expires" CONTENT="Tue, 01 Jan 1980 1:00:00 GMT">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">