キャッシュを無効にする

http://www.crystal-creation.com/web-appli/technical-information/programming/php/network/cache/no-cache/

header( 'Expires: Thu, 01 Jan 1970 00:00:00 GMT' );
header( 'Last-Modified: '.gmdate( 'D, d M Y H:i:s' ).' GMT' );

// HTTP/1.1
header( 'Cache-Control: no-store, no-cache, must-revalidate' );
header( 'Cache-Control: post-check=0, pre-check=0', FALSE );

// HTTP/1.0
header( 'Pragma: no-cache' );