private void Btn_atras_Click(object sender, RoutedEventArgs e)
{
WPF_RegistrarContrato rc = new WPF_RegistrarContrato();
rc.Show();
this.Close();
}
private void Btn_reg_contrato_Click(object sender, RoutedEventArgs e)
{
WPF_RegistrarContrato window = new WPF_RegistrarContrato();
window.Show();
this.Close();
}