ew, and also internally re-order
items within the selected TreeView.  Dragging from selected back to 
source allows items to be deleted.  

Note one other useful feature demonstrated in the sample: when internally
dragging nodes you should never allow a node to be dropped in a position where
it would be made a child of itself.  You can easily check this in cases where
the same item cannot appear more than once in the tree by using the 
the <span class="code">IsParentOf</span> function of the drag
Node on th