      *  Returns the amount one would have to add to the viewport's current 
      *  verticalScrollPosition to scroll by the requested "scrolling" unit.
      * 
-     *  The value of unit must be one of the following flash.ui.Keyboard
-     *  constants: UP, DOWN, PAGE_UP, PAGE_DOWN, HOME, END.
+     *  The value of unit must be one of the following mx.core.ScrollUnit
+     *  constants: LEFT, RIGHT, PAGE_LEFT, PAGE_RIGHT, HOME, END.
      * 
-     *  To scroll by a single row use UP or DOWN and to scroll to the
-     *  first or last row, use HOME or END.
+     *  To scroll by a single column use LEFT or RIGHT and to scroll to the
+     *  first or last column, use HOME or END.
+     * 
+     *  @see ScrollUnit
      */
     function getVerticalScrollPositionDelta(unit:ScrollUnit):Number
      

     */
    function get contentHeight():Number;

     /**
     *  The X coordinate of the origin of the region the target is
     *  scrolled to.  
     * 
     *  Setting this property causes the target's 
     *  <code>scrollRect</code> to be set, if necessary, to:
     *  <pre>
     *  new Rectangle(horizontalScrollPosition, verticalScrollPosition, width, height)
     *  </pre>
     *  Where <code>width</code> and <code>height</code> are properties
     *  of the target.
     * 
     *  Implementations of this property must be Bindable and
     *  they must generate events of type "propertyChange".

     *  The Y coordinate of the origin of the region this Group is
     *  scrolled to.  
     * 
     *  If clipContent is true, stting this property typically causes 
     *  the <code>scrollRect</code> to be set to:
     *  <pre>
     *  new Rectangle(horizontalScrollPosition, verticalScrollPosition, width, height)
     *  </pre>                 
     * 
     *  Implementations of this property must be Bindable and
     *  they must generate events of type "propertyChange".
