private void Btn_Accept(object sender, RoutedEventArgs e)
{
_addedCar.Manufacturer = textBoxManufacturer.Text;
_addedCar.Model = textBoxModel.Text;
_addedCar.Year = int.Parse(textBoxYear.Text);
_addedCar.Fault = textBoxFault.Text;
_addedCar.ArrivalDate = (DateTime)ArrivalDatePicker.SelectedDate;
_addedCar.DepartureDate = (DateTime)DepartureDatePicker.SelectedDate;
_addedCar.OwnerId = comboBoxOwner.SelectedIndex;
_addedCar.ServiceID = comboBoxService.SelectedIndex;
_addedCar.EmployeeID = comboBoxEmployee.SelectedIndex;
CarRepository.AddElement(_addedCar);
//CarsView.Ref
this.Close();
}