code: public static void showDialog(final CmsUUID referenceId, final AsyncCallback<String> createModeCallback) {
  
          CmsRpcAction<CmsListInfoBean> action = new CmsRpcAction<CmsListInfoBean>() {
  
              @Override
              public void execute() {
  
                  start(0, true);
                  CmsCoreProvider.getVfsService().getPageInfo(referenceId, this);
  
              }
  
              @Override
              protected void onResponse(CmsListInfoBean result) {
  
                  stop(false);
                  (new CmsDroppedElementModeSelectionDialog(result, createModeCallback)).center();
              }
          };
          action.execute();
  
      }
docs: Shows the dialog.<p>
  
  @param referenceId the  structure id of the resource for which to load the dialog
  @param createModeCallback the callback to call with the result