public void ReviseMsg(int STDID, string STDN, string CRS, string Exam)
        {
            ComputerEngineeringV v = c.ComputerEngineeringV.Single(x => x.CourseName == CRS);

            m.CourseName = CRS;
            m.StudentID  = STDID; m.StudentName = STDN; m.Exam = Exam; m.Instructer = v.InstructerName;
            c.MarkRevision.Add(m);
            c.SaveChanges();
        }
        public bool Check(string crs, string ins)
        {
            bool Result;
            ComputerEngineeringV v = c.ComputerEngineeringV.Single(x => x.CourseName == crs);

            if (v.InstructerName == ins)
            {
                Result = true;
            }
            else
            {
                Result = false;
            }
            return(Result);
        }