As3 remove current clip if playing - actionscript-3

Question

I have buttons that add movie clips to stage and wont go away when other button is clicked to add another. I've seen similar issues posted but none of the answers worked for me.
btnBlue.addEventListener(MouseEvent.CLICK, fl_MouseOverHandler1);
function fl_MouseOverHandler1(evt: MouseEvent): void {
var ballBlue: BallBlue = new BallBlue;
addChild(ballBlue);
addChildAt(ballBlue, 0);
ballBlue.x = 100; //sets the x position
ballBlue.y = 100; //sets the y position}
function onClick(evt:MouseEvent):void { */to remove clip if one is playing
removeChildAt(0)
}
}
btnRed.addEventListener(MouseEvent.CLICK, fl_MouseOverHandler2);
function fl_MouseOverHandler2(evt: MouseEvent): void {
var ballRed: BallRed = new BallRed;
addChild(ballRed);
addChildAt(ballRed, 0);
ballRed.x = 100; //sets the x position
ballRed.y = 100; //sets the y position}
parent.BallBlue.removeMovieClip();
function onClick(evt:MouseEvent):void { */to remove clip if one is playing
removeChildAt(0)
}
}

Answer 1

btnBlue.addEventListener(MouseEvent.CLICK, btnBlue_clickHandler);
btnRed.addEventListener(MouseEvent.CLICK, btnRed_clickHandler);
var ballBlue: BallBlue = new BallBlue();
var ballRed: BallRed = new BallRed();
function btnBlue_clickHandler(evt:MouseEvent):void {
removeAllBalls();
addChild(ballBlue);
ballBlue.x = 100; //sets the x position
ballBlue.y = 100; //sets the y position
}
function btnRed_clickHandler(evt:MouseEvent):void {
removeAllBalls();
addChild(ballRed);
ballRed.x = 100; //sets the x position
ballRed.y = 100; //sets the y position
}
function removeAllBalls():void {
if (contains(ballBlue))
{
removeChild(ballBlue);
}
if (contains(ballRed))
{
removeChild(ballRed);
}
}