public ActionResult ShowCourse(int id)
        {
            Dictionary <string, object> allInfo  = new Dictionary <string, object>();
            List <StudentClass>         students = JoinTableClass.GetStudentsByCourseId(id);
            List <CourseClass>          course   = CourseClass.FindById(id);

            allInfo.Add("students", students);
            allInfo.Add("course", course);
            return(View("ShowCourse", allInfo));
        }