private void HandleChangeUsernameCommand(object parameter)
 {
     if (DataPersister.ChangeSetting(this.NewUsername, null))
     {
         this.RaiseUsernameChangedSuccess(NewUsername);
         MessageBox.Show("Username changed successfuly!");
     }
 }
        private void HandleChangePasswordCommand(object parameter)
        {
            var passwordBox        = parameter as PasswordBox;
            var password           = passwordBox.Password;
            var authenticationCode = this.GetSha1HashData(password);

            if (DataPersister.ChangeSetting(null, authenticationCode))
            {
                MessageBox.Show("Password changed successfuly!");
            }
        }