How to override extended functions

How to override extended functions

Being a former flash developer, it seems I have been spoiled with certain keywords and concepts. I am trying to override a method from another class that I have extended without using prototype. I am not using prototype because every time I use it, I cannot access local variables (even with getters and setters) locally, which I kind of understand. My other goal is to have local and global variables link to be same variable when I updated locally or from a parent class.

I have shortened these classes to not be so overwhelming.
   
    //doc.js    
    function init(){
         var ballObject = new DragObject("golf_ball.jpg", "golf ball");
         var ballObject2 = new InheritDragObject("golf_hole.jpg", "golf hole");
    }
    
    //DragObject.js
    
    function DragObject (imageReference, imageTitle){
       
         this.__defineGetter__("image", function () {
     return image;
         });
    
         this.__defineSetter__("image", function (val) {
      image = val;
         });
    
         function eventMouseUp(currentEvent){
           //executed event functionality
           $(window).trigger(EVENT_DRAG_UP);
         }
    }
    
    //InheritedDragObject.js
    function InheritDragObject (imageReference, title){
       
         //I cannot access any variables or functions here
         $.extend(true, this, new NewDragDrop(imageReference, title));
    
         function eventMouseUp(currentEvent) {
              //................
              //This is the function I want to override to execute other functionality
         }
    }

So what am I doing wrong? :)