/// <summary>
        /// Handle the New command.
        /// </summary>
        /// <param name="sender">The Add button.</param>
        /// <param name="e">The event arguments.</param>
        private void OnNew(object sender, RoutedEventArgs e)
        {
            WindowAddUser addUser = new WindowAddUser();

            if (this.users.SelectedItem is User)
            {
                addUser.Tenant = (this.users.SelectedItem as User).TenantId;
            }
            else if (this.users.SelectedItem is Tenant)
            {
                addUser.Tenant = (this.users.SelectedItem as Tenant).TenantId;
            }
            else
            {
                addUser.Tenant = this.tenant.TenantId;
            }
            addUser.Owner = this;
            addUser.ShowDialog();
        }
 /// <summary>
 /// Handle a change in selected tenant.
 /// </summary>
 /// <param name="sender">The wizard.</param>
 /// <param name="eventArgs">The event arguments.</param>
 private static void OnTenantChanged(DependencyObject sender, DependencyPropertyChangedEventArgs eventArgs)
 {
     WindowAddUser wizard = sender as WindowAddUser;
 }