Kicking those children OUT

programming flash
1

Here’s the setup
new game screen can go to new game OR how to play screen
how to play screen goes to new game

my doc class pulls both in as per need but I cant figure out how to remove the neccesary child to start into the game. I can get one to work but with both i get:[COLOR=Red] ArgumentError: Error #2025: The supplied DisplayObject must be a child of the caller.
at flash.display::DisplayObjectContainer/removeChild()
at AsteroidSupplyV2/NewGameFCN()
[/COLOR]
here’s the code
package
{
import flash.display.MovieClip
import flash.events.MouseEvent;

public class AsteroidSupplyV2 extends MovieClip
{
    var newGameScreen:NewGameScreen = new NewGameScreen;
    var howToPlayScreen:HowToPlay = new HowToPlay;
    public function AsteroidSupplyV2():void
    {
        trace ("asteroidSupplyV2");
        addChild(newGameScreen);
        newGameScreen.x=width/2;
        newGameScreen.y=height/2
        newGameScreen.newGame_btn.addEventListener(MouseEvent.CLICK,NewGameFCN);
        newGameScreen.howToPlay_btn.addEventListener(MouseEvent.CLICK,howToPlayFCN);
    }
    public function howToPlayFCN(howToPlay_btnEvt:MouseEvent)
    {
        newGameScreen.newGame_btn.removeEventListener(MouseEvent.CLICK,newGameScreen.NewGameFCN);
        newGameScreen.howToPlay_btn.removeEventListener(MouseEvent.CLICK,howToPlayFCN);
        removeChild(newGameScreen);
        addChild(howToPlayScreen);
        howToPlayScreen.x=width/2;
        howToPlayScreen.y=height/2
        howToPlayScreen.newGame_btn.addEventListener(MouseEvent.CLICK,NewGameFCN)
        
    }
    
    
    public function NewGameFCN(newGameFCNEvt:MouseEvent)
    {
        //removeChild(newGameScreen);
        //removeChild(howToPlayScreen);
        removeChild(newGameScreen);
        removeChild(howToPlayScreen);
        trace("NEWGAME!!!")
    }
}

}

HELP!!!:worried: