Add a function to find the real position of the mouse with respect to the page
Add a function to find the real position of the mouse with respect to the page

This is taken from quirksmode.org

fzadow/CATMAID,htem/CATMAID,fzadow/CATMAID,htem/CATMAID,htem/CATMAID,fzadow/CATMAID,htem/CATMAID,fzadow/CATMAID