Getting MovieClips to play randomly PLEASE HELP

I posted this in the Flash 8 forum, but wonder if I’ll have better luck in here. I need to get movie clips to play randomly. Currently, I have actionscript on Frame 1, and a movie clips on the stage in Frame 2. Also in each movie clip as the last frame I have “PlayMC();”. Here’s the ActionScript I’m using now…can anyone provide insight?

var myNumber;
// return a random number
function getRandomNumber(maximum, minimum) {
return Math.floor(Math.random()*maximum)+minimum;
// play a random movieclip
function playMC() {
myNumber = getRandomNumber(3, 1);
// call our playMC function every 15sec
function delayMC() {
myInterval = setInterval(playMC, 15000);
// begin our random movieclips