Actionscript 3 - jigsaw puzzle unloading images

Question

I am using the puzzle game sample from adobe and want to use it as part of an interactive narrative for students. However, everytime I try to go to new frame or scene the image stays with me. How do I remove or unload the puzzle frame and bitmap images so that it doesn't follow me. I am not a coder very confusing here is the entire script.
var puzzlePiecesArr:Array;
var puzzlePiecesFound:Array;
var topDepth:Number;
var totalPuzzlePieces:Number;
var correctPuzzlePieces:Number;
var puzzleBmp:BitmapData;
var intervalID:Number;
var threshold:Number;
var imagesArr:Array;
var imageLoader:Loader;
var requestURL:URLRequest;   
var puzzleBoardClip:MovieClip;
var holder:MovieClip;
init();
function init(){
    puzzleBoardClip = new MovieClip();
    addChild(puzzleBoardClip);
    totalPuzzlePieces = 8;
    //imagesArr = new Array("http://www.helpexamples.com/flash/images/image1.jpg", "http://www.helpexamples.com/flash/images/image2.jpg", "http://www.helpexamples.com/flash/images/image3.jpg");
    imagesArr = new Array("image1.jpg", "image2.jpg", "image3.jpg");
    puzzlePiecesArr = new Array();
    puzzlePiecesFound = new Array();
    correctPuzzlePieces = 0;
    threshold = 0xFFFF;
    /* Create the image Loader */
    imageLoader = new Loader();
    imageLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, onLoadImg);
    /* Create the URL Request */
    var index:Number = Math.floor(Math.random() * imagesArr.length);
    requestURL = new URLRequest(imagesArr[index]);
    // Load the image
    imageLoader.load(requestURL);
    // Setup a holdery mc to hold the puzzle pieces
    holder = new MovieClip();
    addChild(holder);
function onLoadImg(evt:Event):void{
    // Determine the width and height of each puzzle piece.
    // Each puzzle consists of 4 columns and 2 rows.
    var widthPuzzlePiece:Number = imageLoader.width / 4;
    var heightPuzzlePiece:Number = imageLoader.height / 2;
    // Draw the image from the movie clip into a BitmapData Obj.
    puzzleBmp = new BitmapData(imageLoader.width, imageLoader.height);
    puzzleBmp.draw(imageLoader, new Matrix());
    var puzzlePieceBmp:BitmapData;
    var x:Number = 0;
    var y:Number = 0;
    // Loop 8 times to make each piece
    for (var i:Number = 0; i < 8; i++)
        puzzlePieceBmp = new BitmapData(widthPuzzlePiece, heightPuzzlePiece);
        puzzlePieceBmp.copyPixels(puzzleBmp, new Rectangle(x,y,widthPuzzlePiece,heightPuzzlePiece), new Point(0,0));
        makePuzzlePiece(puzzlePieceBmp, i);
        x += widthPuzzlePiece;
        if(x >= puzzleBmp.width)
            x = 0;
            y += heightPuzzlePiece;
    makePuzzleBoard(puzzleBmp.width, puzzleBmp.height);
    arrangePuzzlePieces();
function makePuzzlePiece(puzzlePiece:BitmapData, index:int){
    var puzzlePieceClip:Bitmap = new Bitmap(puzzlePiece);
    var tmp2:MovieClip = new MovieClip();
    tmp2.addChild(puzzlePieceClip);
    tmp2.name = String(index)     // Added for Strict Mode
    holder.addChild(tmp2);
    holder.addEventListener("mouseDown", pieceMove);
    holder.addEventListener("mouseUp", pieceMove);
    puzzlePiecesArr.push(tmp2);
    // This is used to check if the same piece has been placed
    puzzlePiecesFound.push(tmp2.name);
function pieceMove(evt:Event):void{
    if(evt.type == "mouseDown"){
        evt.target.startDrag();
    } else if(evt.type == "mouseUp"){
        evt.target.stopDrag();
        var puzzlePieceIndex:Number = evt.target.name;
        // ADDED VV 4.3. Check if droppped inside of the grid
        if(evt.target.dropTarget){
            var puzzleBoardSpaceIndex:Number = evt.target.dropTarget.name;
        if(puzzlePieceIndex == puzzleBoardSpaceIndex)
            var coordinate:Point = new Point(evt.target.dropTarget.x, evt.target.dropTarget.y);
            var coordinateGlobal:Point = new Point();
            coordinateGlobal = puzzleBoardClip.localToGlobal(coordinate);
            evt.target.x = coordinateGlobal.x;
            evt.target.y = coordinateGlobal.y;
            if(puzzlePiecesFound.length != 0)
                for(var i:int = 0;i < puzzlePiecesFound.length; i++)
                    if(puzzlePiecesFound[i] == puzzlePieceIndex)
                        puzzlePiecesFound[i] = "Correct";
                        correctPuzzlePieces++;
            if(correctPuzzlePieces == totalPuzzlePieces)
                puzzleSolved();
function arrangePuzzlePieces():void
    var widthPuzzlePiece:Number = puzzlePiecesArr[0].width;
    var heightPuzzlePiece:Number = puzzlePiecesArr[0].height;
    var locationArr:Array = new Array();
    locationArr.push({x:10, y:10});
    locationArr.push({x:10 + widthPuzzlePiece + 5, y: 10});
    locationArr.push({x:10, y:10 + heightPuzzlePiece + 5});
    locationArr.push({x:10 + widthPuzzlePiece + 5, y:10 + heightPuzzlePiece + 5});
    locationArr.push({x:10, y:10 + (heightPuzzlePiece + 5) * 2});
    locationArr.push({x:10 + widthPuzzlePiece + 5, y:10 + (heightPuzzlePiece + 5) * 2});
    locationArr.push({x:10, y:10 + (heightPuzzlePiece + 5) * 3});
    locationArr.push({x:10 + widthPuzzlePiece + 5, y:10 + (heightPuzzlePiece + 5) * 3});
    var index:Number = 0;
    var coordinates:Object;
    while(locationArr.length > 0)
        coordinates = locationArr.splice(Math.floor(Math.random() * locationArr.length), 1)[0];
        puzzlePiecesArr[index].x = coordinates.x;
        puzzlePiecesArr[index].y = coordinates.y;
        index++;
function makePuzzleBoard(width:Number, height:Number):void{
    var widthPuzzlePiece:Number = width / 4;
    var heightPuzzlePiece:Number = height / 2;
    var puzzleBoardSpaceClip:MovieClip;
    var x:Number = 0;
    var y:Number = 0;
    for(var i:Number = 0; i < 8; i++)
        puzzleBoardSpaceClip = new MovieClip();
        puzzleBoardSpaceClip.graphics.lineStyle(0);
        puzzleBoardSpaceClip.graphics.beginFill(0xFFFFFF,100);
        puzzleBoardSpaceClip.graphics.lineTo(widthPuzzlePiece,0);
        puzzleBoardSpaceClip.graphics.lineTo(widthPuzzlePiece,heightPuzzlePiece);
        puzzleBoardSpaceClip.graphics.lineTo(0,heightPuzzlePiece);
        puzzleBoardSpaceClip.graphics.lineTo(0,0);
        puzzleBoardSpaceClip.graphics.endFill();
        puzzleBoardSpaceClip.x = x;
        puzzleBoardSpaceClip.y = y;
        x += widthPuzzlePiece;
        if(x >= width)
            x = 0;
            y += heightPuzzlePiece;
        puzzleBoardSpaceClip.name = String(i);    // Added for Strict Mode
        puzzleBoardClip.addChild(puzzleBoardSpaceClip);
    puzzleBoardClip.x = 350;
    puzzleBoardClip.y = 200 - puzzleBoardClip.height/2;
function puzzleSolved():void{
    holder.visible = false;
    var tmp:Bitmap = new Bitmap(puzzleBmp);
    puzzleBoardClip.addChild(tmp);
    var timer:Timer = new Timer(50);
    timer.start();
    timer.addEventListener("timer", puzTrash);
function puzTrash(evt:Event):void{
    if(threshold > 0xFFFFFF)
        threshold = 0xFFFFFF;
        evt.target.stop();
        init();
    puzzleBmp.threshold(puzzleBmp, new Rectangle(0,0, puzzleBmp.width, puzzleBmp.height), new Point(0,0), "<=", 0xFF000000 | threshold);
    threshold *= 1.2;

Answer 1

When you create dynamic content, it does not have a timeline home unless you place it in something that's anchored to the timeline.  What you could do is place the puzzle inside of an empty movieclip that you manually incorporate into the timeline rather than dynamically which you currently do.  For the code you show, you may be able to eliminate this...
var puzzleBoardClip:MovieClip;
and these...
puzzleBoardClip = new MovieClip();
addChild(puzzleBoardClip);
and create an empty movieclip with that instance name that you only allow to exist in the frames where you intend the puzzle to be visible.
Instead, you could also try using: removeChild(puzzleBoardClip);  wherever it is you have code where you would want to make the puzzle no longer visible.