onDrop

fires when the dragged item is dropped

void onDrop(string|number id,string|number pId,number index);

id	string\|number	the dragged item's id
pId	string\|number	the dragged item's new parent id
index	number	the dragged item's new index

myTreeView.attachEvent("onDrop", function(id, pId, index){
    // your code here
});