باسلام وعرض ادب

میخام تو قطعه کد زیر مقدار PrsID رو به Session تخصیص بدم باید چکار کنم؟

 public JsonResult CheckUser(string UserName,string PassWord)
        {
            
            ViewModel.RequestMessage result = new ViewModel.RequestMessage{MessageText = "",Success = false};
            var users = (from item in db.UserBases
                         where (item.UserName.Equals(UserName)) & (item.PassWord.Equals(PassWord))
                         select new ViewModel.UserVM
                         {
                             UserName = item.UserName,
                             FirstName = item.FirstName,
                             LastName = item.LastName,
                             PrsID = item.PrsID
                         }).ToList();
            int a = users.Count;
            if(a!= 0){
                Session["UserName"] = UserName;
                result.Success = true;
                result.MessageText = a.ToString();
            }
              
            else{
                result.Success = false;
                result.MessageText = "UserName Or Password Is Not Valid";
                
            }
            return Json(result, JsonRequestBehavior.AllowGet);
        }
    }