anchor.diff:      _songTitleInput.value = s.title;
       s.readText((String text) {
         _songBodyInput.value = text;  
  -    });
  -
  -    _songTitle.style.display = "none";
  -    _songBodyText.style.display = "none";
  -    _songTitleInput.style.display = "block";
  -    _songBodyInput.style.display = "block";
  -    
  -    _sidebarToggle.disabled = true;
  -    _songEditButton.disabled = true;
  -    _songNewButton.disabled = true;
  -    
  -    _songCancelButton.disabled = false;
  -    _songSaveButton.disabled = false;
  -    
  -    sidebarVisible = false;
  +      _songEditMode = true;
  +      updateUiState();    
  +      sidebarVisible = false;
  +    });
  +
       
     }
     
     void resetUi() {
  -    _songTitle.style.display = "block";
  -    _songBodyText.style.display = "block";
  -    _songTitleInput.style.display = "none";
  -    _songBodyInput.style.display = "none";
  -   
  -    _sidebarToggle.disabled = false;
  -    
  -    _songNewButton.disabled = false;
  -    _songEditButton.disabled = true;
  -    _songDeleteButton.disabled = true;
  -    
  -    _songCancelButton.disabled = true;
  -    _songSaveButton.disabled = true;
  -    
       _songTitle.text = "";
       _songBodyText.text = "";
       
       _songService.activeSong = null;
  -    
  +    _setService.activeSet = null;
       
       sidebarVisible = true;
  +    
  +    _songEditMode = false;
  +    
  +    switchToSongMode();    
     }
     
     void updateUiState() {
  -    
  +    _sidebarToggle.disabled = _songEditMode || _mode == OperatingMode.SET;
  +    
  +    setVisible(_songToolBar, _mode == OperatingMode.SONG);
  +    setVisible(_setToolBar, _mode == OperatingMode.SET);
  +    
  +    _songNewButton.disabled = _songEditMode;
  +    _songSaveButton.disabled = !_songEditMode;
  +    _songCancelButton.disabled = !_songEditMode;
  +    _songEditButton.disabled = _songEditMode;
  +    
  +    setVisible(_songView, _mode == OperatingMode.SONG);
  +    setVisible(_songTitle, !_songEditMode);
  +    setVisible(_songBodyText, !_songEditMode);
  +    setVisible(_songTitleInput, _songEditMode);
  +    setVisible(_songBodyInput, _songEditMode);
  +    
  +    _setBackButton.disabled = _setService.activeSet != null;
  +    _setDeleteButton.disabled = _setService.activeSet != null;
  +    _setEditButton.disabled = _setService.activeSet != null;
  +    
  +    setVisible(_setView, _mode == OperatingMode.SET);
  +    setVisible(_setTitleText, _setService.activeSet != null);
  +    setVisible(_setContentList, _mode == OperatingMode.SET);
  +    
  +    _songStyles.disabled = !(_mode == OperatingMode.SONG);
  +    _setStyles.disabled = !(_mode == OperatingMode.SET);
       
     } 
     
  +  void setVisible(Element elem, bool visible) {
  +    elem.style.display = visible ? "block" : "none";
  +  }
     
     
     void newSong() {
  -    _songTitle.style.display = "none";
  -    _songBodyText.style.display = "none";
  -    _songTitleInput.style.display = "block";
  -    _songBodyInput.style.display = "block";
  -    
  -    _sidebarToggle.disabled = true;
  -    _songEditButton.disabled = true;
  -    _songNewButton.disabled = true;
  -    
  -    _songCancelButton.disabled = false;
  -    _songSaveButton.disabled = false;
  -    
  +    _songEditMode = true;
       sidebarVisible = false;
       _songTitleInput.value = "";
       _songBodyInput.value = "";
       
  +    updateUiState();
  +    
     }
     
     void deleteSong() {
  
positive.code:     _songTitle.text = s.title;
      s.readText((String text) {
        _songBodyText.text = text;
        _songEditButton.disabled = false;
        _songDeleteButton.disabled = false;
        _songService.activeSong = s;
        sidebarVisible = false;
        window.scrollTo(0, 0);
      });
    }
  
negative.code:     _setSaveButton.onClick.listen((e) => saveSet());
      
      _setTitleInput = $("#setTitleInput")[0];
      _setTitleText = $("#setTitleText")[0];
      _setContentList = $("#setContentList")[0];
      _setContentContainer = $("#setContentContainer")[0];
  
  