protected function displayInner() {
    if ($this->_template)  {
      // Get the layout from a template file
      extract($this->_vars);
      include($this->_template);
    }
    else {
      // Echo each child in order
      foreach ($this->_vars as &$child)
        if ($child instanceof Component)
          $child->display();
        else
          echo $child;
    }
  }