Rediect gets stuck in loop

ok i and getting annoyed by this script. i have it all working except for the admin section and this loop

when i login it's supposed to goto the game but instead it goes into a loop and doesn't redirect.

the part thats is giving me trouble is this

if ($isadmin) {
    $incloc="../includes/";
}
if (!$incsetup) {
    require ($incloc."inc-setup.php");
}

might be how i have directory

mydomain.com/ < root

mydomain.com/kp/ < script directory

mydomain.com/kp/includes/ < includes directory

mydomain.com/kp/play/index.php < game, where loop redirect should goto

any help at all?

What kind of loop does it fall into? BTW, maybe require_once() might help instead of require().