function &singleton($user_file = '', $system_file = '', $strict = true)
    {
        if (is_object($GLOBALS['_PEAR_Config_instance'])) {
            return $GLOBALS['_PEAR_Config_instance'];
        }

        $t_conf = &new PEAR_Config($user_file, $system_file, false, $strict);
        if ($t_conf->_errorsFound > 0) {
             return $t_conf->lastError;
        }

        $GLOBALS['_PEAR_Config_instance'] = &$t_conf;
        return $GLOBALS['_PEAR_Config_instance'];
    }