private void cbSanzimanTipi_SelectedIndexChanged(object sender, EventArgs e)
 {
     if (cbSanzimanTipi.SelectedItem.ToString() == "Manuel" || cbSanzimanTipi.SelectedItem.ToString() == "Otomatik")
     {
         cArac a = new cArac();
         dgvAraclar.DataSource = a.AraclariGetirBySanzimanTipi(cbSanzimanTipi.SelectedItem.ToString());
     }
     else
     {
          cArac a = new cArac();
          dgvAraclar.DataSource = a.AraclariGetir();
     }
 }