public ActionResult StudentByClass(int id)
        {
            //   var studentList = db.AspNetStudents.Where(x => x.AspNetStudent_Session_class.Any(y => y.ClassID == id)).Select(x => x.Id).ToList();
            int?sessionId = db.AspNetClasses.Where(x => x.Id == id).FirstOrDefault().SessionID;


            var result1 = db.GetPendingStudentsList(sessionId.ToString());

            //&& !db.StudentFeeMonths.Any(m => m.StudentId == std.Id)
            return(Json(result1, JsonRequestBehavior.AllowGet));
        }