random frame

i have a mc , inside theres 5 frames with stop() scripts , each frame loads a different song.

i want this mc to skip to a random frame everytime it loads so it wont play the same song if lets say the page is refreshed ect.

how would i do that?
thanks.

nevermind i got it ...

i tried using

onClipEvent(enterframe){
gotoandStop(Math.random(5));
}

on the mc but the frames kept looping out of control

so i added this line to the first keyframe in the mc:

gotoandStop(Math.random(5));

that works just as i wanted it to .. jumps to a random frame on load.

but i still would like to know why the onClipEvent one didnt work...