Spot my Query error

[eluser]coolfactor[/eluser]
You've composed a query string, but you haven't executed it to get back a query resultset.

Code:

$query = "SELECT f.email, u.user_id
     FROM forgotten_password AS f
     LEFT JOIN users AS u ON f.email = u.email
     WHERE f.act_key = '$act_key'";

$result = $this->db->query($query);    // <-- you need this or something like it.

if (!$result OR ($result->num_rows() < 1)) {
    show_error('Reset ID passed is not in the database');
}