How to stop the timer and move to next scene when puzzle is solved - actionscript-3

Question

I created a jigsaw in action script and kept it a separate class. In the project i linked the code and i added a timer to the scene so that the player have to solve the puzzle within the time specified. Now what i want is that if the player solved the puzzle correctly the timer will stop and go to next scene.
this is the puzzle.as
var xpos:Array=new Array();
var ypos:Array=new Array();
var numDone,i:int;
var numPieces:int=3;
var dif:int=25; //how close do they have to drag the piece
var sound:Sound=new Sound();
function playSound(file:String): void {
//var sound:Sound=new Sound();
var req:URLRequest=new URLRequest(file);
sound.load(req);
sound.play();
} //playSound
function scramble(): void {
for(i=0;i<numPieces;i++){
this["piece"+i].x=Math.random()*300;
this["piece"+i].y=Math.random()*500;
this["piece"+i].alpha=.8;
} //for each piece
numDone=0;
txtMessage.text="Drag the pieces to solve the puzzle";
sound.close();
} //scramble
function init(): void {
for(i=0;i<numPieces;i++){
xpos[i]=this["piece"+i].x;
ypos[i]=this["piece"+i].y;
this["piece"+i].addEventListener(MouseEvent.MOUSE_DOWN, beginMove);
this["piece"+i].addEventListener(MouseEvent.MOUSE_UP, endMove);
} //for each piece
txtMessage.text="Drag the pieces to solve the puzzle";
} //init
function beginMove(e:MouseEvent): void {
if(e.target.alpha<1)
e.target.startDrag();
} //beginMove
function endMove(e:MouseEvent): void {
if(e.target.alpha<1) {
e.target.stopDrag();
//figure out which piece it is
var piece:int=0;
while(e.target!=this["piece"+piece]){
piece++;
} //
var curX:int=this["piece"+piece].x;
var curY:int=this["piece"+piece].y;
if(curX<=xpos[piece]+dif && curX>=xpos[piece]-dif &&
curY<=ypos[piece]+dif && curY>=ypos[piece]-dif) { //close enough
this["piece"+piece].x=xpos[piece];
this["piece"+piece].y=ypos[piece];
this["piece"+piece].alpha=1;
numDone++;
if(numDone>=numPieces) gameOver();
else playSound("http://www.zebra0.com/langResource/ok.mp3");
} //in position
} //not already done
}//endMove
function gameOver(): void {
txtMessage.text="You did it!";
playSound("http://www.zebra0.com/langResource/win.mp3");
gotoAndStop(1,"Scene 2");
} //gameOver
function scrambleHandler(e:MouseEvent): void {
scramble();
} //clickHandler
btnScramble.addEventListener(MouseEvent.CLICK,scrambleHandler);
function solve(e:MouseEvent): void {
for(i=0;i<numPieces;i++) {
this["piece"+i].x=xpos[i];
this["piece"+i].y=ypos[i];
this["piece"+i].alpha=1;
} //for each piece
} //solve
the code for linking the puzzle.as to the project. i kept in a layer called 'ActionScript'
include "Puzzle.as"
numPieces=20;
init();
scramble();
stop();
timer code i kept in a layer called 'action'
var nCount:Number = 90;
var myTimer:Timer = new Timer(1000, nCount);
timer_txt.text = nCount.toString();
myTimer.start();
myTimer.addEventListener(TimerEvent.TIMER, countdown);
myTimer.addEventListener(TimerEvent.TIMER_COMPLETE, onComplete);
function countdown(e:TimerEvent):void
{
nCount--;
timer_txt.text = nCount.toString();
}
function onComplete(e: TimerEvent):void{
gotoAndStop(35);
}
if any one have an idea of how to achieve this.