private void button3_Click(object sender, EventArgs e)
        {
            Model1 model  = new Model1();
            Doctor doctor = model.Doctor.FirstOrDefault();

            Lek[]        drugList     = DrugView.convertDrugViewToDrug(list);
            Prescription prescription = new Prescription(PrescriptionNumber.getUnusedNumber("Rp"), patient, doctor, drugList);
            //FrmPrescriptionPreview frmPrescriptionPreview = new FrmPrescriptionPreview(prescription);
            //frmPrescriptionPreview.Show();
        }
        void createPrescription()
        {
            Model1 model  = new Model1();
            Doctor doctor = model.Doctor.FirstOrDefault();

            Lek[] drugList = DrugView.convertDrugViewToDrug(list);
            PrescriptionNumber prescriptionNumber = PrescriptionNumber.getUnusedNumber("Rp");

            if (prescriptionNumber != null)
            {
                Prescription prescription = new Prescription(prescriptionNumber, patient, doctor, drugList);
                prescription.insertToDb();
            }
            else
            {
                MessageBox.Show("Brak wolnych numerów recept!");
            }
        }