Unloading an external .swf within itself in action script 3 - actionscript-3

Question

I have been trying to look for a method, I've tried numerous code examples none have worked.
This is the code I'm using in my my main .SWF file to load the external .swf file called (Stage4.swf). How can unload this swf file while it's load within the Stage4.swf file?
var child_loader:Loader = new Loader();
addChild(child_loader);
var url:URLRequest = new URLRequest("Stage4.swf");
child_loader.load(url);
child_loader.contentLoaderInfo.addEventListener(Event.COMPLETE, load_completed);
child_loader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, on_progress);
function load_completed(e:Event):void {
child_loader.x = 0;
child_loader.y = 0;
}
function on_progress(e:ProgressEvent):void {
trace(e.bytesLoaded + " out of " + e.bytesTotal);
}

Answer 1

You should make the child SWF to dispatch a custom Event that will be listened by its parent. Most likely your code snippets don't work because the stack contains the child SWF's code. Something like this:
public static const UNLOAD_SWF:String='unload_swf';
...
function load_completed(e:Event):void {
this.addEventListener(UNLOAD_SWF,doUnload);
// rest of code
}
function doUnload(e:Event):void {
removeEventListener(UNLOAD_SWF,doUnload);
addEventListener(Event.ENTER_FRAME,unloadNow);
}
function unloadNow(e:Event):void {
removeEventListener(Event.ENTER_FRAME,unloadNow);
child_loader.unloadAndStop(); // should work now
}