header ("Expire: Sat,2 Aug 1997 07:07:01 HKT");
header ("Cache-Control: no-store, no-cache, must-revalidate");
header ("Cache-Control: post-check=0, pre-check=0", falase);
header ("Pragma: no-cache");
header ("Cache-Control: no-store, no-cache, must-revalidate");
header ("Cache-Control: post-check=0, pre-check=0", falase);
header ("Pragma: no-cache");
一句就够