private void btnCreateUser_Click(object sender, RoutedEventArgs e)
        {
            string userName = this.userNameBox.Text;
            string password = this.passwordBox.Password;
            string name     = this.nameBox.Text;
            bool   isAdmin  = (bool)this.isAdminCheck.IsChecked;

            UserSyncer userSyncer = new UserSyncer();
            User       user       = userSyncer.WebCreateUser(userName, password, name, isAdmin);

            if (user != null)
            {
                UserPrefs.AddUser(user);
                this.Close();
            }
            else
            {
                MessageBox.Show("User already exists!");
            }
        }