Move nodes to the correspondent folder

How can i do to only allow to move nodes to the correspondent folder?
i.e. A son of History only can be moved to the History

You can check parent’s ID using parameters of “onDrop” event handler and return false if parent IDs are not equal

Thanks for answering.
But you could give me an example of how the method is implemented.

tree1.attachEvent(“onDrop”, function(sId,tId,id,sObject,tObject){
var id_tree1=tree1.getParentId(sId);
var id_tree2 = :question:

return id_tree1==id_tree2;

To provide you a sample i need specify planed drag behaviour. Is it “child” or “complex”?