code: public void reset()
      {
          super.setMinimalWidth(200);
          super.setMinimalHeight(200);
          super.setInitialHeight(400);
          super.setInitialWidth(600);
          super.setUseInitialHeight(true);
          super.setResizable(true);
          super.setHeightUnit("px");
          super.setWidthUnit("px");
          super.setPageCreator(null);
          super.setCloseButtonCallback(null);
          super.setWindowClosedCallback(null);
      }
docs: This method sets this ModalWindowContainer into the state like it was
  just created. It uses the default values as they are defined in
  <code>org.apache.wicket.extensions.ajax.markup.html.modal.ModalWindow
  </code>