loadMovieNum for AS 3.0

var ldr:Loader = new Loader();

 var url:String = "http://www.unknown.example.com/content.swf";
 var urlReq:URLRequest = new URLRequest(url);
 ldr.load(urlReq);
 addChild(ldr);

I think AS3 is far easy comparing to AS2,because there is only one rule for every class or object. Just instantiate it with constructor and work on it I am also intermediate in it, I learn a lot from its documentation. Documentation is great.

To load an swf file using AS3 you use the Loader class (or the UILoader component).  There are no levels in AS3, so the Num element of loadMovieNum doesn't exist.