ERROR in script

De pagina RMAtracking.php wilt niet openen.

<?php
if(mysql_num_rows($result) > 0){
$user_id = $_POST["user_id"];
$paswoord = $_POST["paswoord"];
$_SESSION['user_id'] = $user_id;
$_SESSION['paswoord'] = $paswoord;
header("Location: RMAtracking.php");
exit();
}
?>