public ActionResult Edit(int id, UserVM vm)
 {
     try
     {
         // TODO: Add update logic here
         var locSource = vms.Where(i => i.Id == id).SingleOrDefault();
         locSource.Username = vm.Username;
         return RedirectToAction("Index");
     }
     catch
     {
         return View();
     }
 }
        public ActionResult Create(UserVM vm)
        {
            try
            {
                var id = vms.OrderByDescending(i => i.Id).Select(i => i.Id).FirstOrDefault();
                vm.Id = ++id;
                vms.Add(vm);

                return RedirectToAction("Index");
            }
            catch
            {
                return View();
            }
        }