Problem on display loader

It seems that when I click on next button the previous swf still playing because of the sound embeded on the timeline of the swf.

I know there is something missing in this code.

I already got the current mc = null before the nextScene().

I guess its in the swfLoader1 variable but I'm totally no idea on it.

import flash.display.Loader;

import flash.net.URLRequest;

import flash.events.ProgressEvent;

import flash.events.Event;

import flash.display.MovieClip;

import flash.events.MouseEvent;

var mc1: MovieClip;

var swfLoader1: Loader = new Loader();

var swfUrl1: URLRequest = new URLRequest("scene1.swf");

swfLoader1.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, swfProgressHandler1);

swfLoader1.contentLoaderInfo.addEventListener(Event.COMPLETE, swfLoadedHandler1);

swfLoader1.load(swfUrl1);

movieMC.addChild(swfLoader1);

function swfProgressHandler1(e: ProgressEvent):void{

     var loadPercent: Number = e.bytesLoaded / e.bytesTotal;

     sceneLoaderMC.sceneLoaderBarMC.scaleX = loadPercent;

     sceneLoaderMC.sceneLoaderPercent.text = (Math.ceil(loadPercent * 100)).toString() + "%";

}

function swfLoadedHandler1(e: Event):void{

     swfLoader1.contentLoaderInfo.removeEventListener(Event.COMPLETE, swfLoadedHandler1);

     swfLoader1.contentLoaderInfo.removeEventListener(ProgressEvent.PROGRES S, swfLoadedHandler1);

     sceneLoaderMC.visible = false;

     mc1 = MovieClip(swfLoader1.content);

     mc1.gotoAndPlay(1);

}

function onEnterFrame1(e: Event):void{

          mc1.removeEventListener(Event.ENTER_FRAME, onEnterFrame1);

          mc1 = null;

          nextScene();

     }

}