 import mx.graphics.IGraphicElement;
 import mx.layout.ILayoutItem;
 import mx.core.IViewport;
+import mx.core.ScrollUnit;
 import mx.layout.LayoutBase;
 import mx.layout.BasicLayout;
 import mx.layout.LayoutItemFactory;

    /**
     *  @copy mx.core.IViewport#horizontalScrollPositionDelta
     */
    public function horizontalScrollPositionDelta(unit:uint):Number
    {
        return (layout) ? layout.horizontalScrollPositionDelta(unit) : 0;     
    }
    
    /**
     *  @copy mx.core.IViewport#verticalScrollPositionDelta
     */
    public function verticalScrollPositionDelta(unit:uint):Number
    {
        return (layout) ? layout.verticalScrollPositionDelta(unit) : 0;     
    }
    
    //--------------------------------------------------------------------------


        if (autoLayout && _layout)
            _layout.updateDisplayList(unscaledWidth, unscaledHeight);
            
        if (_layout)
            _layout.updateScrollRect(unscaledWidth, unscaledHeight);
            
    }
    
    //----------------------------------
