Unload and Stop swf from stage

Question

Hi,
I'm a newbie to Flash and Actionscript. I need to give links to around 20 swf files via buttons from the menu.swf. I'm able to give links. But when I come back by clicking HOME button kept at the newly loaded swf the audio files are still being played at the background.
Yes, It has got audio files playing at the back for each slide in the new swfs. When Click on the same link again in menu.swf again the files are being played with the unfinished old file. It's really hectic.
I need to unload it completely from stage when I come back to menu.swf by clicking on HOME button from any of 20 categories.
I used unloadAndStop but it is not doing. I hope that I'm commiting mistakes at somewhere but couldn't predict.
Need some help !
FOR HOME BUTTON:
var _content:Loader = new Loader();
function loadContent(content:String):void {
    if (_content != null) {
        _content.unloadAndStop(true);
        removeChild(_content);
        _content = null;
    var loader:Loader = new Loader();
    loader.load(new URLRequest(content)); //---->>>> I don't really know what should be put in this :-(
    _content = addChild(loader) as Loader;
Home_Button.addEventListener(MouseEvent.CLICK, home);
function home(event:MouseEvent) {
    _content.unloadAndStop(true);
    var homeSWF:URLRequest = new URLRequest("demo.swf");
    _content.load(homeSWF);
    addChild(_content);
FOR MENU.swf button
var loader:Loader = new Loader();
Category1_Button.addEventListener(MouseEvent.CLICK, category1);
function category1(event:MouseEvent):void {
    var Category1SWF:URLRequest = new URLRequest("Category1.swf");
    loader.load(Category1SWF);
    addChild(loader);

Answer 1

Hi,
Can this thread help us?
http://forums.adobe.com/message/3739886
I have seen you have replied to this. Would this give some idea ? Does this script serve the purpose ? I tried replacing the code with appropriate changes and looking like this.
Home Button:
var swf_loader:Loader = new Loader();
///unload previous swf
swf_loader.unloadAndStop();
removeChild(swf_loader);
////load new swf
swf_loader.load(new URLRequest("menu.swf"));
Home_Button.addEventListener(MouseEvent.CLICK, finishLoading);
function finishLoading(e:Event):void{
if(swf_loader.content){
addChildAt(swf_loader, 0);
but getting error as
ArgumentError: Error #2025: The supplied DisplayObject must be a child of the caller.
    at flash.display::DisplayObjectContainer/removeChild()
    at Category1_fla::MainTimeline/frame55()
I think I'm complicating the simple thing.
Thanks.