public ActionResult Create(Student student)
        {
            if (ModelState.IsValid)
            {
                context.Students.Add(student);
                context.SaveChanges();
                return RedirectToAction("Index");
            }

            ViewBag.PossibleCourses = context.Courses;
            return View(student);
        }
 public ActionResult Edit(Student student)
 {
     if (ModelState.IsValid)
     {
         context.Entry(student).State = EntityState.Modified;
         context.SaveChanges();
         return RedirectToAction("Index");
     }
     ViewBag.PossibleCourses = context.Courses;
     return View(student);
 }