public static int DeleteUnreadStudent(string userID, string FlagGrp, string Sender = "-1")
        {
            DataTable dt = null;

            if (userID != null && userID != "" && FlagGrp != "")
            {
                int FlagGrpB = bool.Parse(FlagGrp) == false ? 0 : 1;
                dt = MsgUnReadStudentBuisnes.DeleteUnReadMsgStudent(userID, FlagGrpB, int.Parse(Sender == "" ? "-1" : Sender));
            }
            if (dt != null && dt.Rows.Count > 0)
            {
                return(int.Parse(dt.Rows[0]["CountUnRead"].ToString()));
            }
            else
            {
                return(0);
            }
        }