public function offsetGet($offset)
    {
      // return false if $_FILES['key'] isn't found
      if (!isset($this->_files[$offset])) {
        $this->error = sprintf($this->commonUploadErrors[$this->language]['ERROR_02'], $offset);
        return false;
      }

      $this->_files = $this->_files[$offset];

      // check for common upload errors
      if (isset($this->_files['error'])) {
        $this->error = $this->commonUploadErrors[$this->language][$this->_files['error']];
      }

      return true;
    }