anchor.diff:    render() {
       var _items = [];
       for (var item in items) {
  +      var className = '';
         if (selected.value == item) {
  -        _items.add(span({'ref' : '$item', 'key': item,
  -          'onMouseDown': (ev) => mouseDown(ev, item),
  -          'className' : 'selected'}, item));
  +        className = 'selected';
  +      } else if (active.value == item) {
  +        className = 'active';
  +      } else if (loading.value == item) {
  +        className = 'loading';
         }
  -      else if (active.value == item) {
  -        _items.add(span({'ref' : '$item', 'key': item,
  -          'onMouseDown': (ev) => mouseDown(ev, item),
  -          'className' : 'active'}, item));
  -      }
  -      else if (loading.value == item) {
  -        _items.add(span({'ref' : '$item', 'key': item,
  -          'onMouseDown': (ev) => mouseDown(ev, item),
  -          'className' : 'loading'}, item));
  -      }
  -      else {
  -        _items.add(span({'ref' : '$item', 'key': item,
  -          'onMouseDown': (ev) => mouseDown(ev, item)}, item));
  -      }
  +      _items.add(span({'ref' : '$item', 'key': item,
  +        'onMouseDown': (ev) => mouseDown(ev, item),
  +        'className' : '$className'}, item));
       }
   
       var leftArrowButton = div({'key': 'leftArrowButton', 'onMouseDown': (ev) =>
  -        arrowLeftRightMouseDown(ev, true)}, '<');
  +        scroll(toLeft: true)}, '<');
       var rightArrowButton = div({'key': 'rightArrowButton', 'onMouseDown': (ev) =>
  -        arrowLeftRightMouseDown(ev, false)}, '>');
  +        scroll(toLeft: false)}, '>');
   
       var textSpan = span({'key': selectorText,
         'className' : 'round-selector-text'}, selectorText);
  
positive.code:     loading.value = item;
    }
  
    arrowLeftRightMouseDown(ev,isLeft) {
      var _itemSpan = ref(items[0].toString());
      var _scrollListDiv = ref('round-list');
      var _visibleItemsWindowSize = scrollStep * _itemSpan.marginEdge.width;
  
negative.code:     _scrollStep = _scrollStep.replaceAll('px','');
      _scrollStep = num.parse(_scrollStep).round();
  
      if (toLeft) {
        _scrollStep += _visibleItemsWindowSize;
      }
      else {
  