// GET: Submission
        public ActionResult Index(int?id)
        {
            if (id.HasValue && (User.IsInRole("Teacher") || _submissionService.VerifyUser(User.Identity.Name, id.Value)))
            {
                var model = _submissionService.GetSubmissionById(id.Value);

                ViewBag.UserName = User.Identity.Name;
                return(View(model));
            }

            if (User.IsInRole("Teacher"))
            {
                return(RedirectToAction("Index", "Teacher"));
            }
            else
            {
                return(RedirectToAction("Index", "Student"));
            }
        }