code: public void removeButton(Widget w) {
  
          m_buttonPanel.remove(w);
          if (CmsCoreProvider.get().isIe7()) {
              m_buttonPanel.getElement().getStyle().setWidth(m_buttonPanel.getWidgetCount() * 22, Unit.PX);
          }
      }
docs: Removes a widget from the button panel.<p>
  
  @param w the widget to remove