code: public void addBottomWidget(Widget w) {
  
          m_content.removeStyleName(I_CmsLayoutBundle.INSTANCE.dialogCss().alertMainContent());
          m_bottomWidgets.getElement().getStyle().clearDisplay();
          m_bottomWidgets.add(w);
  
      }
docs: Adds a widget to this dialogs bottom content.<p>
  
  @param w the widget to add