[flexcoders] How can I get the item's new parent node when drag a tree item to itself

[zedan_gu]

The tree dataPrivoder
  <xml>
     <node id='1' label='A' />
     <node id='2' label='B'>
         <node id='3' label='C'/>
         <node id='4' label='D'/>
     </node>
  </xml>
 Now, I want drag the node(id=3,label=C) [marked as N3] to
node(id=1,label=A) [marked as N1] on the tree, and this will set new
tree be
   <xml>
     <node id='1' label='A' >
         <node id='3' label='C'/>
     </node>
     <node id='2' label='B'>
         <node id='4' label='D'/>
     </node>
  </xml> .
 In the dragDrop event or dragComplete event, I want to get [N3]'s
paraent node id (N1 id =1 in this case), and how can I get the item's
new parent node when drag a tree item to itself.
 In my case, I will set dragMoveEnabled="false", so after dragComplete
the tree will the same as before, until it be done by some code I
written, anybody help me?