Drag and drop for tree

Hi all,
I want to add a drop drag feature to a tree.
Here some experiment code for that?

setup_drag_drop: function() {
		// experimental
		var me = this;
		if(this.tree.drop && this.parent_label) {
			this.$ul.droppable({
				hoverClass: "tree-hover",
				greedy: true,
				drop: function(event, ui) {
					event.preventDefault();
					var dragged_node = $(ui.draggable).find(".tree-link:first").data("node");
					var dropped_node = $(this).parent().find(".tree-link:first").data("node");
					me.tree.drop(dragged_node, dropped_node, $(ui.draggable), $(this));
					return false;
				}
			});
		}

can anyone give me some hints in order to do that?
Thanks
Maysaa

Any suggesstion plz?