(AS2) Help with AI >Trying to make a swarming flying<

1

Before i post the AS. this is how i program.

I program (not on frames). I bring in CLASSes by calls…
I.E enemy.as

I have all my ships flying in, Blowing up, Ect… now i wanna give it some tweaks…

–SCRIPT–
“I’m trying to give it a more Bubbled swarm effect, As reading i can use Math.sin( );
but im not sure how ima pull this off” after reading my book, There programming is a bit critical compared to what i’ve already written, Im trying to not just fly it vertical up and down. stop. (zigzag) for thoughs who don’t know. But try to make them come in like a swarm half circles down up, and random."

class Enemy extends MovieClip
{
var speed;
var shoottimer;
var ySpeed;

function onLoad()

{
_x = 700;
ySpeed = 1;
_y = Math.random()*200 + 50;
speed = 5;
shoottimer = 0;

}

function onEnterFrame()
{

_x -= speed;
_y += ySpeed * 2;

if(ySpeed == 1 && _y &gt; 250)
    {
        
        ySpeed = -1;
    }
    else if(ySpeed == -1 && _y &lt; 50)
    {
        
        ySpeed = 1;
    }

//Removing clip if.
if(_x &lt; -100)
{
    this.removeMovieClip();
}

if(this.hitTest(_root.ship))
{
    explode();
}


shoottimer +=1;
if(shoottimer &gt; 30)
{
shoottimer = 0;
var missile = _root.attachMovie("EnemyMissile","EnemyMissile" + _root.getNextHighestDepth(), _root.getNextHighestDepth());
missile._x = _x - 50;
missile._y = _y + 2;

}

}

function explode()
{
var explosion = _root.attachMovie( "Fexpo" , "Fexpo" +     _root.getNextHighestDepth(), _root.getNextHighestDepth() );
explosion._x = _x;
explosion._y = _y;
this.removeMovieClip();
_root.ship.updateScore(50);
}

}

theres the script so far, Flawless as it works. But i want to add whats missing. .
Any Takers?.