Communicate with external loaded SWF

1

I am building a highscore system for my site, and I was wondering how to communicate with classes that are included in an external swf that i’ve loaded in.

Basically, how does mindjolt do this:


var urlLoader:Loader = new Loader();
  urlLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, loadFinished);
  urlLoader.load(new URLRequest(gameParams.mjPath || "http://static.mindjolt.com/api/as3/api_as3_local.swf"));
  this.addChild(urlLoader);
  function loadFinished (e:Event):void {
    MindJoltAPI=e.currentTarget.content;
    if (MindJoltAPI != null) {
      MindJoltAPI.service.connect(postMindJoltAPIConnect);
      trace ("[MindJoltAPI] service successfully loaded");
    } else {
      trace("[MindJoltAPI] failed to load");
    }
  }

then somehow they can do this:


MindJoltAPI=e.currentTarget.content;
    //and this
      MindJoltAPI.service.connect(postMindJoltAPIConnect);

How do they/I do that?