public ActionResult Join(int?id) { if (id != null) { Course course = db.Courses.Find(id); ApplicationUser student = db.Users.Find(User.Identity.GetUserId()); UserRepository urepository = new UserRepository(); if (!urepository.checkIfRequestExists(student, course.Teacher, course, "JoinCourse")) { CoursesRepository repository = new CoursesRepository(); repository.CreateJoinRequest(student, course); return(RedirectToAction("Index_ToSelect", course.Teacher)); } else { TempData["Message"] = "There is already a request for this course!!!"; return(RedirectToAction("Index_ToSelect", course.Teacher)); } } else { return(new HttpStatusCodeResult(HttpStatusCode.BadRequest)); } }