code:
//Do this when the game loads
createEmptyMovieClip("airplanes");
createEmptyMovieClip("bombs");
maxtime=30
//Do this when your creating the movies
airplanes.attachMovie("aircraft", "aircraft" + p, p);
airplanes["aircraft" + p].current=0
airplanes["aircraft" + p].interval=random(maxtime)
p++
//Do this everyframe
for(plane in airplanes){
airplanes[plane]._x+=xspeed
airplanes[plane].current++
if(airplanes[plane].current==airplanes[plane].interval){
bombs.attachMovie("bomb", "bomb" + p, p);
bombs["bomb"+p]._x=airplanes[plane]._x
bombs["bomb"+p]._y=airplanes[plane]._y
airplanes[plane].interval=random(maxtime) }
}
for(bomb in bombs){
bombs[bomb]._y+=bombyspeed
//Do whatever actions bombs do
}