class Abstract extends MovieClip
{
	public function attach():Abstract
	{
		var depth:Number   = this.getNextHighestDepth();
		var linkage:String = "child";
		var name:String    = linkage + depth;
		
		return Abstract(this.attachMovie(linkage, name, depth));
	}
}

class Child extends Abstract
{

}

trace(this.abstract.attach());