 import mx.events.PropertyChangeEvent;
 import mx.components.baseClasses.FxComponent;
 import mx.core.ScrollPolicy;
+import mx.core.ScrollUnit;
 import mx.managers.IFocusManagerComponent;
 
     

     *  The viewport component to be scrolled.
     * 
     *  <p>The viewport is added to the FXScroller component's skin 
     *  which lays out both the viewport and scrollbars.</p>
     */
    public function get viewport():IViewport
    {       

            verticalScrollBar.viewport = null;        
        if (skin && viewport)
        {
            viewport.clipContent = false;
            skin.removeItem(viewport);
            viewport.removeEventListener(PropertyChangeEvent.PROPERTY_CHANGE, viewport_propertyChangeHandler);
        }
