public ActionResult _Register(string cnum, string semester)
        {
            string           username = HttpContext.User.Identity.Name;
            CourseRegisterVM crvm     = new CourseRegisterVM();
            bool             add      = BusinessRegistrar.SignUpCourse(username, cnum, semester);

            crvm.SList = BusinessRegistrar.GetSemester();
            crvm.SelectedCoursesNum = cnum;
            crvm.SelectedSemester   = semester;
            crvm.CList         = BusinessRegistrar.GetCoursesForSemester(crvm.SelectedSemester);
            crvm.EList         = BusinessRegistrar.GetEnrollmentForACourse(null, username);
            crvm.AddCourse     = add;
            crvm.ClickRegister = true;
            if (add)
            {
                return(RedirectToAction("CourseRegister"));
            }
            else
            {
                ViewBag.Message = "Fail.";
                return(View());
            }
        }