         super.partAdded(partName, instance);
         
         if (instance == verticalScrollBar)
-        {
             verticalScrollBar.viewport = viewport;            
-            verticalScrollBar.addEventListener("valueCommit", vsb_valueCommitHandler);
-        }
         
         if (instance == horizontalScrollBar)
-        {
             horizontalScrollBar.viewport = viewport;            
-            horizontalScrollBar.addEventListener("valueCommit", hsb_valueCommitHandler);
-        }
     }
     
     /**

        super.partRemoved(partName, instance);
        
        if (instance == verticalScrollBar)
        {
            verticalScrollBar.viewport = null;
            verticalScrollBar.removeEventListener("valueCommit", vsb_valueCommitHandler);
        }
        
        if (instance == horizontalScrollBar)
        {
            horizontalScrollBar.viewport = null;
            horizontalScrollBar.removeEventListener("valueCommit", hsb_valueCommitHandler);
        }
    }
    
    /**

    // Event Handlers
    //
    //--------------------------------------------------------------------------

    
    private function viewport_propertyChangeHandler(event:PropertyChangeEvent):void
    {
    	switch(event.property) 
    	{
    		case "contentWidth": 
    		case "contentHeight": 
                invalidateSkin();
    		    break;
        }
    }
    
    //--------------------------------------------------------------------------
    //
