HELP: When hitting Refresh I still get old data ..

Hi! Here is my scenario. I'm doing a dynamic html with php for my address book. When I enter all the data that is necesary and hit Submit, for saving the user( using POST), I get an error or success message, which is OK, but if I press a Refresh button now, it will try to save the user again, because old data is still in the $_POST.Why?? I already tried header directives: 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",false); // HTTP/1.1 header("Cache-Control: post-check=0, pre-check=0", false); header("Pragma: no-cache"); Thx, Krispi