While you modify element or add widget, you must return app       function listBoxClick( eventInfo ) {   var app = UiApp.getActiveApplication();   Logger.log( "listBoxClick: "  +  eventInfo.parameter.searchListbox );       var text = app.getElementById( "text" );   text.setText( eventInfo.parameter.searchListbox );      var title = app.getElementById( "title" );   title.setText( eventInfo.parameter.searchListbox );      return app; }