code: public void show() {
  
          if (m_isFrame) {
              RootPanel root = RootPanel.get();
              root.getElement().getStyle().setMargin(0, Unit.PX);
              root.getElement().getStyle().setPadding(0, Unit.PX);
              RootPanel.get().add(m_main);
              m_isShowing = true;
              Scheduler.get().scheduleDeferred(new ScheduledCommand() {
  
                  public void execute() {
  
                      adjustContentSize();
                  }
              });
          } else {
              m_popup.center();
          }
  
      }
docs: Shows the dialog.<p>