Error 2025 with eventlistener

programming flash
1

a function generating the game buttons

public function showGameButton(buttonLabel:String,Name:String,xcord:int,ycord:int) {
   gameButton = new GameButton();
   gameButton.label.text = buttonLabel;
   gameButton.x = xcord;
   gameButton.y = ycord;
   gameSprite.addChild(gameButton);
   gameButton.name=Name;
   addChild(gameButton);
   trace(getChildByName("gobtn"))
   
  }

another that access it


public function xmlLoaded(event:Event) {
   dataXML  = XML(event.target.data);
   gameSprite.removeChild(messageField);
   messageField = createText("Get ready for the first question!",questionFormat,gameSprite,0,60,800);
   showGameButton("GO!","gobtn",350,550);
   gobtn=MovieClip(getChildByName("gobtn"));
   gobtn.addEventListener(MouseEvent.CLICK,pressedGameButton);
  }

and I get error 2025 something about the parent, does anyone know how to resolve it?

Many thanks