Dropped Position on a Page when using a draggable element


I am playing with droppable elements and rjs.

I have a simple question. I have setup my whole page as been able to
receive events when an object is dropped on it. It works.

Anyone knows:

  • How to get the coordinates on the page the object was dropped? so for
    example I can update a database in the backend.
  • How to force on display an object to be displayed at a certain
    position on a page?

any help would be very helpful.