private void EdytujKontrahenta()
{
var id = Int32.Parse(GridGlowny.SelectedRows[0].Cells["Id"].Value.ToString());
FormKontrah form = new FormKontrah(id);
form.ShowDialog();
}
private void ButtonNowyKontrahent_Click(object sender, System.EventArgs e)
{
FormKontrah form = new FormKontrah();
form.ShowDialog();
AktualizujListeKontrahentow();
}