public string Create(WorkingDays mast)
 {
     try
     {
         var salarymast = new MonthlySalaryMast();
         var salarydetails = new List<MonthlySalaryDetail>();
         salarymast.Branchid = mast.Branchid;
         salarymast.Month = mast.Month;
         salarymast.Year = mast.Year;
         salarymast.Totaldaysinmonth = mast.Totaldaysinmonth;
         var monthlySalaryDetails = mast.WorkingDaysDetails.Select(x =>
             new MonthlySalaryDetail
             {
                 EmpId = x.EmpId,
                 AttendanceDays = x.AttendanceDays,
                 Holidays = x.Holidays,
                 LeaveDays = x.LeaveDays,
                 AbsentDays = x.AbsentDays,
                 PayDays = x.PayDays,
                 OTHours = x.OTHours
             }
         );
         salarymast.MonthlySalaryDetails = monthlySalaryDetails.ToList();
         Service.Add(salarymast);
         return "Working Days Saved Successfully";
     }
     catch (Exception ex)
     {
         ModelState.AddModelError("Error", ex.Message);
         return ex.Message;
         throw new ArgumentException(ex.Message);
     }
 }
        public ActionResult Edit(MonthlySalaryMast workingDaysEntry)
        {
            if (ModelState.IsValid)
            {
                Service.Update(workingDaysEntry);
                return RedirectToAction("Index");
            }

            return View(workingDaysEntry);
        }