How to detect swf has finished playing. in this context

I am using the loader class to load an external swf “cube_final.swf”.
please note I am setting a movie_clip (set on stage) to alpha=0 as I want it to remain invisble until the loaded swf finishes playing. I will then set alpha = 100% .

But how to i detect that the swf has finished playing? I can detect whether its loaded (i’ll place a preloader in the loading() function)

I am new to action scripting, so any pointers would be welcomed.

this.open_cube.alpha = 0

var introLoader:Loader;

function loadIntro(url:String):void {
// Set properties on my Loader object
introLoader = new Loader();
introLoader.load(new URLRequest(url));
introLoader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, introLoading);
introLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, introLoaded);


function introLoaded(e:Event):void {
// Load SWF file

function introLoading(e:ProgressEvent):void {