Actually, what might work better (since setInterval is independent of framerate, and might be unfair to people with slower machines), is to have a simple counter function that runs onEnterFrame. Something like this:
Code Select
var waveCounter:Number = 0;
var timesUp:Number = 5000;
function increaseCounter () {
waveCounter++;
if (waveCounter>= timesUp) {
launchNewWave();
waveCounter = 0;
}
}