I posted this in the "Using the DOM" sub-forum, but have been unlucky so far, so my apologies for re-posting here.

How do I work out the coordinates of an item on the screen so that I can place the top-left-hand corner of a layer there?

I have a cell in a table (which I've given an ID to be able to refer to it). I need a layer to be displayed at the top-left of this cell. Obviously, I cannot predict where the cell will be in absolute x-y terms, so how do I read it's co-ordinates from the DOM?

All help gratefully appreciated.