firebug warning with keydown events

firebug warning with keydown events

Hi Folks,


why does FireBug show a warning like,
" the charCode property of a keydown event should not be used. It's value is meaningless"

if I bind a keydown/keyup event to the document itself?
It's just a warning, but it's a little bit annoying and must have a reason?


Kind Regards
--Andy