public createEmptyMovieClip(name:String, depth:Number) : MovieClip
Creates an empty movie clip as a child of an existing movie clip. This method behaves similarly to the attachMovie() method, but you don't need to provide an external linkage identifier for the new movie clip. The registration point for a newly created empty movie clip is the upper-left corner. This method fails if any of the parameters are missing.
You can extend the methods and event handlers of the MovieClip class by creating a subclass.
name:String - A string that identifies the instance name of the new movie clip.
depth:Number - An integer that specifies the depth of the new movie clip.
MovieClip - A reference to the newly created movie clip.
The following example creates an empty MovieClip named container, creates a new TextField inside of it, and then sets the new TextField.text property.
var container:MovieClip = this.createEmptyMovieClip("container", this.getNextHighestDepth());
var label:TextField = container.createTextField("label", 1, 0, 0, 150, 20);
label.text = "Hello World";