public ActionResult Index(int id)
        {
            var course = CourseServiceCaller.Get(id);

            ViewBag.CourseName = course.Name;
            ViewBag.CourseId   = id;
            var noteList = NoteServiceCaller.GetAll().Where(x => x.CourseId == id);

            return(View(noteList));
        }
        public ActionResult AddNote(int id, string content)
        {
            var course = CourseServiceCaller.Get(id);

            var newNote = new NoteModel()
            {
                CourseName  = course.Name,
                CourseId    = course.Id,
                Information = content
            };

            ViewBag.CourseId = id;
            NoteServiceCaller.Add(newNote);
            return(RedirectToAction("Index", new { Id = id }));
        }