I may be wrong but I think the syntax should be:

loadMovieNum("buttons.swf",2);

I load a navigation system via loadMovie but it does not work on forst frame
On fram 1 I have:
loadMovie("buttons.swf", "_level2");
stop();

On frame 2
stop();
this._level2._x = 200;
this._level2.retroceder_btn.onRelease = function(){
_root.gotoAndPlay(1);
}
this._level2.avanzar_btn.onRelease = function(){
_root.gotoAndPlay(3);

On frame 3:
stop()
this._level2.retroceder_btn.onRelease = function(){
_root.gotoAndPlay(2);
}
this._level2.avanzar_btn.onRelease = function(){
_root.gotoAndPlay(3);
}

Why doesnt this code work on frame 1 when I place it there:

this._level2.retroceder_btn.onRelease = function(){
_root.gotoAndPlay(1);
}
this._level2.avanzar_btn.onRelease = function(){
_root.gotoAndPlay(2);

Moock says it cant be because its in the same stament block so I cant
acces the methdos and properties of the loaded clip on the 1st frame So