Не сохраняются данные в MS SQL

public void NewRow(CurrencyManager crm)
{
	crm.AddNew();
	drvCars = (DataRowView)crm.Current;
	ds = (Dataset) drvCars.Row.Table.DataSet;;

	vueCities = ds.Cities_list.DefaultView;
	vueCities.Sort = "city_name";
	vueCars_list = ds.Cars_list.DefaultView;
	vueCars_list.Sort = "car_model";

	drvCars["send_date"] = DateTime.Now;

	deCarsDataSend.DataBindings.Add("EditValue", drvCars,"send_date");
	txtRPay.DataBindings.Add("EditValue",drvCars, "rpay");
			
	FillCombo(vueCities); //Заполнение ComboBox'ов
					cbCitiesList.DataBindings.Add("EditValue", drvCars, "city_id");
	cbCarsList.DataBindings.Add("EditValue", drvCars, "car_id");

	if(this.ShowDialog() == DialogResult.OK)
	{
		CargoDB.frmMain.daCars.Update(ds.Cars);
	}

if(this.ShowDialog() == DialogResult.OK)
{
	drvCars.BeginEdit();
	drvCars["city_id"] = (int)(cbCitiesList.EditValue);
	drvCars["send_date"] = deCarsDataSend.DateTime;
	drvCars["car_id"] = (int)(cbCarsList.EditValue);
	if (txtRPay.Text == String.Empty)
	{
		drvCars["rpay"] = DBNull.Value;
	}
	else
	{
		drvCars["rpay"] = Convert.ToInt16(txtRPay.Text);
	}
	drvCars.EndEdit();
	if(ds.HasChanges())
	{
		CargoDB.frmMain.daCars.Update(ds.Cars);
	}
}
else
{
	drvCars.CancelEdit();
}