function isLoggedIn()
    {
        session_start();
        $this->user = $_SESSION['username'];
        $this->pass = $_SESSION['password'];
        $this->mysql->query("SELECT * FROM users WHERE username = '"
                .$this->user."' AND password = '".$this->pass."'");
        $result = $this->mysql->lastQuery();
        if(mysql_num_rows($result) == 0)
        {
            header("Location: ../expired.php");
            die();
        }
        $result_array = mysql_fetch_array($result);
        $this->id = $result_array['id'];
        $this->user = $result_array['username'];
        $this->password = $result_array['password'];
        $this->email = $result_array['email'];
        return 1;
    }