MVC Redirect problem

[jxah152]

I'm working on a registration system. When after a user has selected a session to attend and filled out the info they are sent to a 'registrationController.php' file that checks their info for problems, scheduling them if there aren't any. After being scheduled they are sent to a confirmation page via a header redirect. The problem is if you refresh that confirmation page, the registrationController.php code is run again as if it's being included, but it's not. (Or is it for some reason?)

It goes something like this -->
registrationController.php:
<?
// get sessions to register for
// check info
// if bad send back
// if good schedule

// send to confirmation page

?>

confirmation.php displays confirmation info, but if you refresh that page the code from registrationController.php is executed again...

Thanks for any insight!