This event calls user-defined handlers (if there are any) and passes the following parameters:
  sId - id of the source item (id after inserting into the tree, may not be equal to the initial id);  
 
  tId - id of the target item;
 
  id - if the node is dropped as a sibling, id of the item before which the source node will be inserted;
 
  sObject - source tree object;
 
  tObject - target tree object.
 
           tree.attachEvent("onDrop", function(sId,tId,id,sObject,tObject){});