Accessing display object on the stage from another class

Question

I've googled this to no avail, I've only found how to manipulate the stage itself and not a display object on it, and I'm noob enough to not be able to figure it out from there. :/
I have a movie clip on the main timeline with instance name displayName. I created a button that should change what frame displayName goes to (in order to...did you guess it?! diplay the Name of the button. Awesome. )
So I am trying to write the code in a reusable fashion and have the buttons all linked to a class called GeoPuzzle. Inside GeoPuzzle I instantiate a touch event and run the code. However, the function has to be able to change displayName in the main part of the timeline and, of course, the compiler says displayName doesn't exist because I'm in a class and I'm talking about the stage.
Here is the simplified code in the class:
package  com.freerangeeggheads.puzzleography {
    import flash.display.MovieClip;
    import flash.events.TouchEvent;
    public class GeoPuzzle extends MovieClip {
        //declare variables
        public function setInitial (abbrev:String, fullName:String, isLocked:Boolean):void {
            //set parameters
            this.addEventListener(TouchEvent.TOUCH_BEGIN, geoTouchBeginHandler);
        public function GeoPuzzle (): void {
        public function geoTouchBeginHandler (e:TouchEvent): void {
               e.target.addEventListener(TouchEvent.TOUCH_END, geoTouchEndHandler);
               //some other methods
               nameDisplay.gotoAndStop(e.target.abbrev);
        public function geoTouchEndHandler (e:TouchEvent): void {
            //some other methods
           nameDisplay.gotoAndStop("USA");
The lines in bold are my problem. Now this code doesn't actually execute as is so if you see an error in it, yeah, I have no idea what the problem is, but it DID execute before and these lines still gave me trouble so I'm trying to troubleshoot on multiple fronts.
How can I tell displayName to change it's current frame from within display object class?
Thanks!

Answer 1

if displayName is a GeoPuzzle instance, use:
package  com.freerangeeggheads.puzzleography {
    import flash.display.MovieClip;
    import flash.events.TouchEvent;
    public class GeoPuzzle extends MovieClip {
        //declare variables
        public function setInitial (abbrev:String, fullName:String, isLocked:Boolean):void {
            //set parameters
            this.addEventListener(TouchEvent.TOUCH_BEGIN, geoTouchBeginHandler);
        public function GeoPuzzle (): void {
        public function geoTouchBeginHandler (e:TouchEvent): void {
               e.target.addEventListener(TouchEvent.TOUCH_END, geoTouchEndHandler);
               //some other methods
               this.gotoAndStop(this.abbrev);
        public function geoTouchEndHandler (e:TouchEvent): void {
            //some other methods
           this.gotoAndStop("USA");