private void AddButton_Click(object sender, EventArgs e)
{
Car <string> car = (Car <string>)CarCBox.SelectedItem;
Payment payment = (Payment)PaymentCBox.SelectedItem;
Specialist specialist = (Specialist)SpecialistCBox.SelectedItem;
TimeSpan ts = (TimeSpan)TimeCBox.SelectedItem;
contractLogic.Add(new Contract(specialist.ID, car.ID, DatePicker.Value, ts, DefectTBox.Text, payment.ID));
Close();
}
