I need to overlay some elements where the "id" attribute isn't set.
The documentation suggests manipulating the DOM to set it manually,
which I am doing with some javascript that is sourced in my XUL file
and called on window "load" event. Using DOM inspector I can see the
"id" attributes getting set, but my overlay items aren't working. I'm
guessing this is because the javascript happens *after* the overlay is
merged? Can anyone suggest a way of doing this?