private function _getPath($fileName = null)
    {
        $level = $this->_level;
        if ($fileName) {
            return OPENBIZ_LOG_PATH . '/' . $fileName . $this->_extension;
        }
        switch ($this->_org) {
            case 'DATE':
                return OPENBIZ_LOG_PATH . '/' . date("Y_m_d") . $this->_extension;
            case 'LEVEL':
                $level = $this->_level2filename($level);
                return OPENBIZ_LOG_PATH . '/' . $level . $this->_extension;
            case 'LEVEL-DATE':
                $level = $this->_level2filename($level);
                //delete old log files                
                if ($this->_daystolive > 0) {
                    if (is_array(glob(OPENBIZ_LOG_PATH . '/' . $level . '-*' . $this->_extension))) {
                        foreach (glob(OPENBIZ_LOG_PATH . '/' . $level . '-*' . $this->_extension) as $filename) {
                            $mtime = filemtime($filename);
                            if ((time() - $mtime) >= $this->_daystolive * 86400) {
                                @unlink($filename);
                            }
                        }
                    }
                }
                return OPENBIZ_LOG_PATH . '/' . $level . '-' . date("Y_m_d") . $this->_extension;
            case 'PROFILE':
                $profile = Openbizx::$app->getUserProfile('USERID');
                if (!$profile) {
                    $profile = 'Guest';
                }
                return OPENBIZ_LOG_PATH . '/' . $profile . $this->_extension;
            default:
                break;
        }
    }