public function next_pic(arch):Sprite
		{
			var count = 0;
			var list:Array = get_list(arch);

			for each (var o in list) {
				if(o.used == true) {
					count ++;
					continue;
				}
				o.used = true;
				// "sprite" is actually a dispaly frame at the moment
				o.sprite.id = arch + ":" + count;
				return o.sprite;
			}
			throw new Error("No free pics for archetype '" + arch + "'");
			return null;
		}