Need advice for spawn system

1

I just need to know how to do it correctly… So I can spawn enemies, and NOT have the depths of their projectiles overlapping.

Any guides/advice appreciated! Btw… Heres my progress so far:
Arrow keys, ctrl-cannon, mouse-missile.
http://photobucket.com/albums/y232/minyMonkey/?action=view&current=tank.swf

Prototypes within classes is that… Okay? LoL! My problem is… The depths of the projectiles overlap… When I create more than one enemeyTurret.

If I increase the counter… It works fine, which does not make sense, because both start counting at the same time, and should overlap depths.

I just set the bullet number to 200, and made six start firing simoultainiously… The depths do not overlap. I don’t get it?


class enemyTurret extends MovieClip {
    private function onEnterFrame() {
        this._x += _root.landSpeed;
    }
    private function onLoad() {
        var bullet = 1;
        MovieClip.prototype.fireEnemyCannon = function() {
            if (bullet>=10) {
                bullet = 0;
            }
_root.enemyBullet0.duplicateMovieClip("enemyBullet"+(bullet++), bullet+200, {_visible:true, _rotation:this.launchB.r, _x:this.launchB.x, _y:this.launchB.y, gravity:.25, speed:15, friction:.99});
        };
    }
}