Aliens

package {

    import flash.display.MovieClip;
    import flash.events.MouseEvent;
    import flash.events.Event;

    public class movingAliensCode extends MovieClip {

        public function movingAliensCode() {

            // variables

            var aNum: Number = 0;
            var aArray: Array = new Array();
            var aCheck: Boolean = false;
            var speed: Number = 5;
            var drop: Boolean = true;

            // on load

            var sb: startbutton = new startbutton();
            addChild(sb);
            sb.x = 275;
            sb.y = 300;
            sb.buttonMode = true;

            // events

            sb.addEventListener(MouseEvent.CLICK, startFun);
            function startFun(e: MouseEvent): void {
                placeAliensOnStage();
                moveStartButton();
            }

            addEventListener(Event.ENTER_FRAME, mainFun);
            function mainFun(e: Event): void {

                moveAliens();

            }

            // functions

            function moveAliens(): void {
                for (var i: Number = 0; i < aArray.length; i++) {

                    aArray[i].x += speed;
                    if (aArray[i].x > 550 || aArray[i].x < 0) {

                        aCheck = true;

                    }

                }
                if (aCheck == true) {
                    speed *= -1;
                    aCheck = false;
                }

            }

            function moveStartButton(): void {
                sb.x = 11100;
                sb.y = 4124123;
            }

            function placeAliensOnStage(): void {

                for (var i: Number = 0; i < 5; i++) {

                    for (var j: Number = 0; j < 11; j++) {

                        if (i < 1) {
                            var a3: alien3 = new alien3();
                            aArray.push(a3);
                        } else if (i < 3) {
                            var a2: alien2 = new alien2();
                            aArray.push(a2);
                        } else if (i < 5) {
                            var a1: alien1 = new alien1();
                            aArray.push(a1);
                        }
                        addChild(aArray[aArray.length - 1]);
                        aArray[aNum].x = j * 30;
                        aArray[aNum].y = i * 30;
                        aNum++;
                    }
                }
            }

        }

    }

}