Word to ya motha's

I have a 'snail racing' game where there is ONE user controlled MC and the other THREE MC's are running on there own timeline.

But the thing is i dont want the other 3 'opponant' MC's to be the same all the time because when a user comes back they will realise that there are only 3 mc's that always play the same.

How do i make the movie load random MC's everytime i load the SWF? (so that the competition is a little different)

Thankyou for the help in advance

Gav