Flash Player 4.
_levelN
Property; a reference to the root movie Timeline of _levelN. You must use the loadMovieNum action to load movies into the Flash Player before you use the _level property to target them. You can also use _levelN to target a loaded movie at the level assigned by N.
The initial movie loaded into an instance of the Flash Player is automatically loaded into _level0. The movie in _level0 sets the frame rate, background color, and frame size for all subsequently loaded movies. Movies are then stacked in higher-numbered levels above the movie in _level0.
You must assign a level to each movie that you load into the Flash Player using the loadMovieNum action. You can assign levels in any order. If you assign a level that already contains a SWF file (including _level0) the movie at that level is unloaded and replaced by the new movie.
The following example stops the playhead in the main Timeline of the movie in _level9.
_level9.stop();
The following example sends the playhead in the main Timeline of the movie in _level4 to Frame 5. The movie in _level4 must have previously been loaded with a loadMovieNum action.
_level4.gotoAndStop(5);
loadMovie(), MovieClip.swapDepths()