Drag&Drop works in each tree and between trees too.
<div id="treeboxbox_tree" style="width:200;height:200"></div>
<script>
tree=new dhtmlXTreeObject("treeboxbox_tree","100%","100%",0);
tree.setImagePath("../imgs/");
//enable Drag&Drop
tree.enableDragAndDrop(1);
//set my Drag&Drop handler
tree.setDragHandler(myDragHandler);
tree.loadXML("tree.xml");
function myDragHandler(idFrom,idTo){
//if we return false then drag&drop be aborted
return true;
}
</script>