1. In PHP:

//code for clearing cache.

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-store, no-cache, must-revalidate"); // HTTP/1.1 header("Cache-Control: post-check=0, pre-check=0", false); header ("Pragma: no-cache"); // HTTP/1.0

 
2. In html : put this code in head tag:

//For avoiding cache problem

<META HTTP-EQUIV="Pragma" CONTENT="no-cache"> <META HTTP-EQUIV="Cache-Control" CONTENT="no-cache"> <META HTTP-EQUIV="Pragma-directive" CONTENT="no-cache"> <META HTTP-EQUIV="Cache-Directive" CONTENT="no-cache"> <META HTTP-EQUIV="Expires" CONTENT="0">