session_start();
if(!isset($_POST['s']) and !isset($_SESSION['s'])){

echo '
<form action="index.php" method="post" accept-charset="utf-8">
	<input type="password" name="s">
	<input type="submit">
</form>
';
exit();
}

$s=$_POST['s'];
$gs="88*99-55/";

if($s == $gs){
	$_SESSION['s'] = $s;
	echo $_SESSION['s'];
}elseif($_SESSION['s'] != $gs){
	echo "bu sayfayı görüntülemeye yetkiniz yok. post: ".$s;
	header ("refresh:10;Location:index.php");
	exit();
}