public ActionResult DeleteCourseFromClass(int class_id)
        {
            ClassCourseViewModel model = new ClassCourseViewModel();

            model.ClassId = class_id;
            return(View(model));
        }
        public ActionResult DeleteCourseFromClass(ClassCourseViewModel model)
        {
            ClassCourses cc = data_storage.ClassCourses.Where(c => c.ClassId.Equals(model.ClassId) && c.CourseId.Equals(model.CourseId)).First();

            data_storage.ClassCourses.Remove(cc);
            data_storage.SaveChangesAsync();
            return(RedirectToAction($"EditClass/{model.ClassId}"));
        }
        public ActionResult AddCourseToClass(int class_id)
        {
            ClassCourseViewModel model = new ClassCourseViewModel();

            model.ClassId = class_id;

            return(View(model));;
        }
        public ActionResult AddCourseToClass(ClassCourseViewModel model)
        {
            var course = data_storage.Courses.Where(c => c.CourseId.Equals(model.CourseId));

            if (course.Count() == 0)
            {
                return(View(model));
            }
            string _coursename = course.First().CourseName;

            data_storage.ClassCourses.Add(new ClassCourses()
            {
                ClassId    = model.ClassId,
                CourseId   = model.ClassId,
                CourseName = _coursename
            });
            data_storage.SaveChangesAsync();
            return(RedirectToAction($"EditClass/{model.ClassId}"));
        }