private void ButtonLogin_Click(object sender, RoutedEventArgs e)
{
string account = textboxAccountNumber.Text;
string pin = textboxPin.Password;
token = bank.Authorize(account, pin);
if (token.Length == 0)
{
labelLoginError.Content = "Podane dane logowania są niepoprawne";
}
else
{
ClearAll();
gridLogin.Visibility = Visibility.Hidden;
gridClientPanel.Visibility = Visibility.Visible;
RefreshBalance();
labelCurrency.Content = bank.GetCurrency(token);
}
}