MySli bind_param issue (receiving server error(500))

Question

I've been trying to find out what's giving me this error 500 on my server. i've been trying to add some prepared statements to my server for some password checking. But I do have an error on the bind_param line that makes all of it returning an error 500. I can't find out where's the mistake and why it's failing.

$password = $_GET['p'];
$query = $db->prepare("SELECT * FROM ItemPassTable WHERE Password = ?");

$query->bind_param("s", $password);
if($query->execute())
{
    $res = $query->get_result();
    if ($row = $res->fetch_assoc()) {

        header("Location: moveTo.php?pointingto=$password");
        die();
    }
}