public function getParam($name)
  {
    //if (in_array($name, self::$_textParamNames)) {
    if (in_array($name, $this->_textParamNames)) {
      return $this->_textParams[$name];
    } else {
      throw new CPS_Exception(array(array('long_message' => 'Invalid response parameter', 'code' => ERROR_CODE_INVALID_PARAMETER, 'level' => 'REJECTED', 'source' => 'CPS_API')));
    }
  }