DisplayObject error

programming flash
1

i’m looping though a display object and trying to reset some button. the issue i’m having is i’m getting and error:
1119: Access of possibly undefined property menuText through a reference with static type flash.display:DisplayObject.

on the line where i try and target obj.menuText below. the weird thing is that this same code works when the actionscript isn’t in a document class. i think i’m importing all the classes i need. also in the document class i had to add the MovieClip(obj) as pointed out below or i’d get an error similar to the one about. any idea why moving this into a package is causing this?

public function resetMenu() {
//Loop through all of the menu itemsd
for (var i:int=0; i<menuHolder.numChildren; i++) {

            var obj:DisplayObject=menuHolder.getChildAt(i);

            //Set menu button to Off state
            TweenMax.to(obj.menuText,1,{tint:0x000000});  // GET ERROR HERE
            //Make menu button active and add listeners
            MovieClip(obj).mouseEnabled=true; //NOT IN PACKAGE THIS WAS JUST obj.mouseEnabled=
            obj.addEventListener(MouseEvent.MOUSE_OVER,mouseOverItem,false,0,true);
            obj.addEventListener(MouseEvent.MOUSE_OUT,mouseOutItem,false,0,true);
            obj.addEventListener(MouseEvent.CLICK,itemClicked,false,0,true);
        }
    }