Posting variable in url

I have a redirect that if conditions are right it will pass the user to a new page via $_POST. so for instance the redirect looks like this: header("Location: more_registration.php?username=".$_POST["username"]."&email=".$_POST["email"]); the url will look like this: http://ftudor/test/more_registration.php?username=1234&email=a@a.com the form componement on the new page looks like this: <form method="post" action="<?php echo $PHP_SELF; ?>"> <input name="username" type="hidden" value="<?php echo $_GET['username']; ?>" size="15"> <input name="email" type="hidden" value="<?php echo $_GET['email']; ?>" size="15"> </form> I am posting variables in the url and on this next page more form stuff awaits the user. If a user submits incorrect stuff in the form is posts to itself. The url holds the same variables that were pass through the redirect. My concern is that if a variable got altered in the URL by misstake or on purpose it would post to the refreshed page and screw everything up. Anyone run into something like this? Frank __________________________________ Do you Yahoo!? Exclusive Video Premiere - Britney Spears http://launch.yahoo.com/promos/britneyspears/