anchor.diff:        appendOuput('No subscription, cannot cancel!');
       }
     }
  -  
  +
     void appendOuput(String text) {
  -    output.appendText('$text\n');
  +    output.value += '$text\n';
       output.scrollTop = output.scrollHeight;
     }
   }
  
positive.code: void main() {
    // Init logging.
    initLogging();
    
    // Log all events.
    eventBus.on().listen((event) => _log.finest('event fired:  ${event.runtimeType}'));
    
    
    // Initialize the listener boxes.
    Listener listener1 = new Listener(querySelector('#listener-1'));
    Listener listener2 = new Listener(querySelector('#listener-2'));
    
    // Init Event fields.
    LabelElement fireLabelA = querySelector('#fire-label-a');
    LabelElement fireLabelB = querySelector('#fire-label-b');
    ButtonElement fireButtonA = querySelector("#fire-button-a");
    ButtonElement fireButtonB = querySelector("#fire-button-b");
    
    fireButtonA.onClick.listen((_) {
      // -------------------------------------------------
      // Fire Event A
  
negative.code:       appendOuput('No subscription, cannot pause!');
      }
    }
  
    void resume() {
      if (subscription != null) {
        subscription.resume();
  