public function validateLogin($username, $password) {
        $username = mysql_real_escape_string($username);
        $password = mysql_real_escape_string(hash('sha512', $password));


        $mysql_num_rows = mysql_num_rows(mysql_query("SELECT * FROM users WHERE (username = '" . $username . "') && (password = '" . $password . "') && (validated='1')") or die(mysql_error()));
        if ($mysql_num_rows == 1) {
            $_SESSION['username'] = $username;
            $userid = mysql_fetch_array(mysql_query("SELECT userid FROM users WHERE username = '" . $username . "'"));
            $_SESSION['userid'] = $userid['userid'];
            return TRUE;
        }
        else {
            return FALSE;
        }
    }