Drag events from dhtmlx list to dhtmlx scheduler

1.We want to implement drag and drop feature from dhtmlx list to dhtmlx scheduler .
2.We have implemented drag and drop feature ,we have used these cdn link “http://cdn.dhtmlx.com/edge/dhtmlx.js” and “http://cdn.dhtmlx.com/edge/dhtmlx.css”.
3)On calling the function scheduler.attachEvent(“onExternalDragIn”,function(id,source,ev){}. We are getting (source.parentObject). undefined.
4)Instead of dragging single list item all the items are dragged at once into the scheduler.
5)We want to remove the particular list item from the list after i has been dragged into the scheduler.For that, we would need the id of that particular list item and we are not able to get that id by source.parentObject.id.Instead we are getting complete div of listbox in the source.

Could you please, clarify your usecase with some code snipept or a complete demo, where the porblem can be reconstructed.