How do I drag and drop multiple objects in a mask?

Question

I’ve been working on a flash simulator to show what our night vision product would look like in the dark.  I have been successful in making it work with the following code below.  Yet I cannot add a "reticle" image (or symbol) to the draggable mask to make it work.  Can someone help me with the code?  I looked for hours on the internet and I cannot get it to work.  I am new to Flash but am starting to learn as much as I can.
Actionscript 3 Code:
img_nv.mask = mask_mc;
mask_mc.buttonMode = true;
mask_mc.addEventListener(MouseEvent.MOUSE_DOWN, dF);
stage.addEventListener(MouseEvent.MOUSE_UP, dropF);
function dF(event:MouseEvent):void{
          mask_mc.startDrag();
function dropF(event:MouseEvent):void{
          mask_mc.stopDrag();

Answer 1

use a loop (like enterframe) and update the reticle's position to match mask_mc's position.
mg_nv.mask = mask_mc;
mask_mc.buttonMode = true;
// eg, if you add reticle_mc to the stage in the authoring environment
removeChild(reticle_mc);
mask_mc.addEventListener(MouseEvent.MOUSE_DOWN, dF);
stage.addEventListener(MouseEvent.MOUSE_UP, dropF);
function dF(event:MouseEvent):void{
addChild(reticle_mc);
this.addEventListener(Event.ENTER_FRAME,reticleF);
          mask_mc.startDrag();
function dropF(event:MouseEvent):void{
removeChild(reticle_mc);
this.removeEventListener(Event.ENTER_FRAME,reticleF);
          mask_mc.stopDrag();
function reticleF(e:Event):void{
reticle_mc.x=mask_mc.x;  // assuming they both have the same reg points (like the center)
reticle_mc.y=mask_mc.y;