public string GetAllOnlineUsers()
        {
            JSonResult result = new JSonResult();
            result.Status = false;

            List<OnlineUser> onlineUsers = new List<OnlineUser>();
            Chat chat = new Chat();

            List<OnlineUser> ou = new List<OnlineUser>();

            DataSet allUsersDataset = chat.GetAllOnlineUsers();
            foreach (DataRow dr in allUsersDataset.Tables[0].Rows)
            {
                onlineUsers.Add (new OnlineUser(dr[0].ToString(), dr[1].ToString()));
                ou.Add(new OnlineUser(dr[0].ToString(), dr[1].ToString()));
            }

            result.Status = true;
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            string jsonresult = serializer.Serialize(ou);

            return jsonresult;
        }