public ActionResult Set(int id)
        {
            try
            {
                ProgressReportModel viewModel = new ProgressReportModel();

                viewModel.ProblemSet = GlobalStaticVars.StaticCore.GetSetById(id);
                viewModel.StudentProgressList = GlobalStaticVars.StaticCore.GetStudentProgress(viewModel.ProblemSet.Class.Id, id);
                viewModel.ProblemProgressList = GlobalStaticVars.StaticCore.GetProblemProgress(viewModel.ProblemSet.Class.Id, 0, id);

                return View(viewModel);
            }
            catch
            {
                return RedirectToAction("ServerError", "Error");
            }
        }
        public ActionResult Class(int id)
        {
            try
            {
                if ((int) Session["ClassId"] != id || (UserType) Session["UserType"] != UserType.Instructor)
                {
                    return RedirectToAction("Unauthorized", "Error");
                }

                ProgressReportModel viewModel = new ProgressReportModel();

                viewModel.Class = GlobalStaticVars.StaticCore.GetClassById(id);
                viewModel.StudentProgressList = GlobalStaticVars.StaticCore.GetStudentProgress(id);
                viewModel.SetProgressList = GlobalStaticVars.StaticCore.GetSetProgress(id);
                viewModel.ProblemProgressList = GlobalStaticVars.StaticCore.GetProblemProgress(id);

                return View(viewModel);
            }
            catch
            {
                return RedirectToAction("ServerError", "Error");
            }
        }
        public ActionResult Student(int id)
        {
            try
            {
                ProgressReportModel viewModel = new ProgressReportModel();

                viewModel.User = GlobalStaticVars.StaticCore.GetUserById(id);
                viewModel.SetProgressList = GlobalStaticVars.StaticCore.GetSetProgress((int)Session["ClassId"], id);
                viewModel.ProblemProgressList = GlobalStaticVars.StaticCore.GetProblemProgress((int)Session["ClassId"], id);

                return View(viewModel);
            }
            catch
            {
                return RedirectToAction("ServerError", "Error");
            }
        }