Code:
//setup
var hotspots:Array = new Array();
for (var i:uint = 0; i < numChildren; i++){
  if (getChildAt(i).name.indexOf("hotspot") == 0){
    hotspots.push(getChildAt(i));
  }
}

//alpha call.
for (var i:uint = 0; hotspots.length; i++) {
	hotspots[i].alpha = 0;
	trace(hotspots[i].alpha);
}
Or did you mean example of the recursive function?