public ActionResult Disputes()
        {
            var dalHelper    = new DalHelper();
            var courseResult = dalHelper.GetProfessorCoursesByUser(HttpContext.User.Identity.Name);

            if (courseResult.HasError)
            {
                throw new InvalidOperationException(courseResult.Message);
            }

            if (courseResult.Value == null || !courseResult.Value.Any())
            {
                return(View(new DisputesViewModel()));
            }

            var disputeResult = dalHelper.GetDisputesByCourseId(courseResult.Value.FirstOrDefault().Id);

            if (disputeResult.HasError)
            {
                throw new InvalidOperationException(disputeResult.Message);
            }

            var disputes = disputeResult.Value;
            var model    = new DisputesViewModel
            {
                AvailableCourses  = courseResult.Value,
                AvailableDisputes = disputes
            };

            return(View(model));
        }
        public PartialViewResult GetDisputeCourses(int courseId)
        {
            var dalHelper     = new DalHelper();
            var disputeResult = dalHelper.GetDisputesByCourseId(courseId);

            if (disputeResult.HasError)
            {
                throw new InvalidOperationException(disputeResult.Message);
            }

            var model = new DisputesViewModel {
                AvailableDisputes = disputeResult.Value
            };

            return(PartialView("DisputeCourse", model));
        }