multiple users and default browser

i have 2 users on win xp, i'd like to set my default browser to moz, and the
other user's default to ie.
so far i haven't been able to get it to work,  does anyone know of a way to
do this?
i tried the axx and defaults thing under xp and it seems to make the change
system wide.. not user, and same with the box that pops up and does a
default browswer check
any ideas or help would be appr..