public ActionResult Index(UserLookupViewModel vm)
        {
            if (ModelState.IsValid)
                vm.User = _graphConnection.GetUser(vm.UserId.Value);
            else
                vm.UserId = null;

            return View(vm);
        }
        public ActionResult Index(UserLookupViewModel vm)
        {
            if (ModelState.IsValid)
            {
                vm.User = _graphConnection.GetUser(vm.UserId.Value);
            }
            else
            {
                vm.UserId = null;
            }

            return(View(vm));
        }