private void OnUserAutoCompleteBoxPopulating(object sender, PopulatingEventArgs e)
        {
            var acb = sender as AutoCompleteBox;

            if (acb != null)
            {
                var context = new SystemUserDomainContext();
                context.SearchUser(e.Parameter, (obj) =>
                {
                    if (Utility.Utility.CheckInvokeOperation(obj))
                    {
                        acb.ItemsSource = obj.Value;
                    }
                }, null);
            }
        }