Layer problems with youtube embed and button in Flash AS3

I'm using the YouTube embed API (https://developers.google.com/youtub..._api_reference) to stream a YouTube clip inside a swf file. I have put a transparent button directly into the stage but once the YouTube clip is loaded, it keeps appearing over the button.

How can I change the layer order so that the button always stays at the top?

Here is my AS3 code to embed the YouTube clip…

Code:

---

// This will hold the API player instance once it is initialized.
var player:Object;

var loader:Loader = new Loader();

var context:LoaderContext = new LoaderContext();
context.checkPolicyFile = true;
context.securityDomain = SecurityDomain.currentDomain;
context.applicationDomain = ApplicationDomain.currentDomain;

loader.contentLoaderInfo.addEventListener(Event.INIT, onLoaderInit);
Security.allowDomain("www.youtube.com")
loader.load(new URLRequest("http://www.youtube.com/v/Z3wnzmJBCDo?version=3&rel=0&autoplay=1&controls=1&showinfo=0&modestbranding=1"));

function onLoaderInit(event:Event):void {
    addChild(loader);
    loader.content.addEventListener("onReady", onPlayerReady);
    loader.content.addEventListener("onError", onPlayerError);
    loader.content.addEventListener("onStateChange", onPlayerStateChange);
    loader.content.addEventListener("onPlaybackQualityChange", onVideoPlaybackQualityChange);
}

function onPlayerReady(event:Event):void {
  // Event.data contains the event parameter, which is the Player API ID
trace("player ready:", Object(event).data);

// Once this event has been dispatched by the player, we can use
// cueVideoById, loadVideoById, cueVideoByUrl and loadVideoByUrl
// to load a particular YouTube video.
player = loader.content;
// Set appropriate player dimensions for your application
player.setSize(300, 250);

}

function onPlayerError(event:Event):void {
// Event.data contains the event parameter, which is the error code
trace("player error:", Object(event).data);
}

function onPlayerStateChange(event:Event):void {
// Event.data contains the event parameter, which is the new player state
trace("player state:", Object(event).data);
}

function onVideoPlaybackQualityChange(event:Event):void {
// Event.data contains the event parameter, which is the new video quality
trace("video quality:", Object(event).data);
}

---

Thanks very much,

James