About at 1:00 am of the second night after we checked in, there was a man knock at my roomdoor very loudly, he claimed to be a security of this hotel, I don't understand what happened, why he need to knock at roomdoor after midnight, We really scare it, and we want to know why. Next morning we reported it to the front desk, required hotel to investagate it and give us a feedback, but up to now, no any answer to us.