Scratch

class EnemyShip extends MovieClip
{
    var speed;
    var shootTimer;
    
    function onLoad()
    {
        _x = 700
        _y = Math.random()*250 + 50;
        speed = Math.random()*5 + 5;
        shootTimer = 0;
    }
    
    function onEnterFrame()
    {
        _x -= speed;
        if(_x < -100)
        {
                this.removeMovieClip();
        }
        if(this.hitTest(_root.ship))
        { 
            explode();
        }
        
        shootTimer +=1;
        if(shootTimer > 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("Explosion","Explosion" + _root.getNextHighestDepth()._root.getNextHighestDepth());
        explosion._x = _x;
        explosion._y = _y;
        this.removeMovieClip();
    }