get html element from point

hi,
I'm using Mozila firefox and i want to write a function that get x,y coordinates and return the HtmlElement that is in this position .

somthing like : GetHTMLElementFrom point(x,y) ... return Html Object Name

i don't know event where to start.

thank u!

I know that jkd has written a function to do this. I have the code, but I can't really post it here on his behalf, as it's not mine... I'll let him know about this thread though.