Moving Background Based Mouse Movement (Parallax) AS3

Question

I found this AS2 tutorial online but I'd like to achieve this in AS3. I tried transcribing but the  setProperty is throwing me off. Thanks
//AS 2 parallax code
stageWidth = Stage.width;
speed1 = 20;
speed2 = 19;
mc1Width = front_mc._width;
mc2Width = back_mc._width;
mc1X = front_mc._x;
mc2X = back_mc._x;
lock_scroll = false;
_root.onEnterFrame = function () {
    if (!lock_scroll)
        scroll_mc();
function scroll_mc() {
    var xdist = _xmouse-(stageWidth/2);
    mc1X += -xdist/speed1;
    mc2X += -xdist/speed2;
    if (mc1X>=0) {
        mc1X = 0;
    if (mc1X<=stageWidth-mc1Width) {
        mc1X = stageWidth-mc1Width;
    if (mc2X>=0) {
        mc2X = 0;
    if (mc2X<=stageWidth-mc2Width) {
        mc2X = stageWidth-mc2Width;
    setProperty("front_mc", _x, mc1X);
    setProperty("back_mc", _x, mc2X);
//create an empty mc container for content to display
createEmptyMovieClip("content_box", 200);
content_box._x = 195;
content_box._y = 92;

Answer 1

Ok I added that line of code. But my background isn't moving...
var stageWidth:Number = stage.width;
var speed1:Number = 20;
var speed2:Number = 19;
var mc1Width = front_mc.width;
var mc2Width = back_mc.width;
var mc1X:Number = front_mc.x;
var mc2X:Number = back_mc.x;
var lock_scroll:Boolean = false;
stage.addEventListener(Event.ENTER_FRAME, scroll_mc);
function scroll_mc(event:Event):void
        //if (!lock_scroll)
                var xdistance = mouseX-(stageWidth/2);
                mc1X += -xdistance/speed1;
                mc2X += -xdistance/speed2;
                if (mc1X>=0)
                    mc1X = 0;
                if (mc1X<=stageWidth-mc1Width)
                    mc1X = stageWidth-mc1Width;
                if (mc2X>=0)
                    mc2X = 0;
                if (mc2X<=stageWidth-mc2Width)
                    mc2X = stageWidth-mc2Width;
                back_mc.x=mc1X;
                front_mc.x=mc2X;