private void UpdateCustomer()
{
Musteri musteri = new Musteri();
musteri.Ad = txtAd.Text;
musteri.Soyad = txtSoyad.Text;
musteri.TelNo = masktxtTel.Text;
musteri.MusteriTurId = int.Parse(comboBox1.SelectedValue.ToString());
musteriBusiness.UpdateCustomer(musteri, degiscekMusteri);
}