Can someone explain what this actionscript means?

1

can someone please explain what does this actionscript will do ?

 onClipEvent (enterFrame) {
	if (this._x<0) {
		this._y = -30;
		radius = (Math.floor(Math.random()*(50-10))+10);
		xcenter = (Math.floor(Math.random()*(440-35))+35);
		speed = (Math.floor(Math.random()*(3-1))+1);
	}
	if (this._x>500) {
		this._y = -30;
		radius = (Math.floor(Math.random()*(50-10))+10);
		xcenter = (Math.floor(Math.random()*(440-35))+35);
		speed = (Math.floor(Math.random()*(3-1))+1);
	}
	if (this._y>450) {
		this._y = -30;
		radius = (Math.floor(Math.random()*(50-10))+10);
		xcenter = (Math.floor(Math.random()*(440-35))+35);
		speed = (Math.floor(Math.random()*(3-1))+1);
	}
	if (_root.w == 0) {
		_root.fireb = 1;
		_root.p += 1;
		duplicateMovieClip(_root.bebullet, "bebullet"+_root.p, _root.p);
		_root.w = (Math.floor(Math.random()*(125-75))+75);
	} else {
		_root.w -= 1;
	}
	degree += speed;
	radian = (degree/45)*Math.PI;
	this._x = xcenter+Math.cos(radian)*radius;
	this._y += 1;
}

This

 onClipEvent (enterFrame) {
	if (this._x<0) {
		this._y = -30;
		radius = (Math.floor(Math.random()*(50-10))+10);
		xcenter = (Math.floor(Math.random()*(440-35))+35);
		speed = (Math.floor(Math.random()*(3-1))+1);
	}
	if (this._x>500) {
		this._y = -30;
		radius = (Math.floor(Math.random()*(50-10))+10);
		xcenter = (Math.floor(Math.random()*(440-35))+35);
		speed = (Math.floor(Math.random()*(3-1))+1);
	}
	if (this._y>450) {
		this._y = -30;
		radius = (Math.floor(Math.random()*(50-10))+10);
		xcenter = (Math.floor(Math.random()*(440-35))+35);
		speed = (Math.floor(Math.random()*(3-1))+1);
	}
	if (_root.w == 0) {
		_root.fireb = 1;
		_root.p += 1;
		duplicateMovieClip(_root.bebullet, "bebullet"+_root.p, _root.p);
		_root.w = (Math.floor(Math.random()*(125-75))+75);
	} else {
		_root.w -= 1;
	}
	degree += speed;
	radian = (degree/45)*Math.PI;
	this._x = xcenter+Math.cos(radian)*radius;
	this._y += 1;
}

and this

 onClipEvent (enterFrame) {
	if (this, hitTest(_root.enemya)) {
		_root.blasta2._x = _root.enemya._x;
		_root.blasta2._y = _root.enemya._y;
		tellTarget (_root.blasta2) {
			gotoAndPlay(1);
		}
		_root.enemya._y = -30;
		_root.enemya.radius = (Math.floor(Math.random()*(50-10))+10);
		_root.enemya.speed = (Math.floor(Math.random()*(3-1))+1);
		_root.enemya.xcenter = Math.floor(Math.random()*(450))+15;
		_root.score += 10;
		if (this != _level0.bullet) {
			this.removeMovieClip();
		}
	}
	if (this, hitTest(_root.enemyb)) {
		_root.blastb2._x = _root.enemyb._x;
		_root.blastb2._y = _root.enemyb._y;
		tellTarget (_root.blastb2) {
			gotoAndPlay(1);
		}
		_root.enemyb._y = -30;
		_root.enemyb.radius = (Math.floor(Math.random()*(50-10))+10);
		_root.enemyb.xcenter = Math.floor(Math.random()*(450))+15;
		_root.enemyb.speed = (Math.floor(Math.random()*(3-1))+1);
		_root.score += 10;
		if (this != _level0.bullet) {
			this.removeMovieClip();
		}
	}
	if (this != _level0.bullet) {
		if (_root.fire == 1) {
			this._y -= 5;
			this._visible = 1;
		}
		if (this._y<0) {
			this.removeMovieClip();
		}
	}
}

thank you .