function &throwError($message = null, $code = null, $userinfo = null)
    {
        if (isset($this) && is_a($this, 'PEAR')) {
            $a = &$this->raiseError($message, $code, null, null, $userinfo);
            return $a;
        }

        $a = &PEAR::raiseError($message, $code, null, null, $userinfo);
        return $a;
    }