protected void saveBillButton_Click(object sender, EventArgs e)
        {
            Patient aPatient = new Patient();

            aPatient.Name        = nameOfPatientTextBox.Text;
            aPatient.DateOfBirth = dateTextBox.Text;
            aPatient.Mobile      = mobileTextBox.Text;
            string patientSaved = aPatientManager.SavePatient(aPatient);

            Bill        aBill     = new Bill();
            List <Bill> aBillList = (List <Bill>)ViewState["Bill"];

            string billSave = "";

            if (patientSaved == "Patient saved")
            {
                DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
                long     ms    = (long)(DateTime.UtcNow - epoch).TotalMilliseconds;
                ViewState["BillNo"] = ms.ToString();

                foreach (Bill Bill in aBillList)
                {
                    aBill.TestName  = Bill.TestName;
                    aBill.Fee       = Bill.Fee;
                    aBill.BillNo    = ms.ToString();
                    aBill.Total     = (double)ViewState["Total"];
                    aBill.PatientId = aPatientManager.GetPatientId(aPatient.Mobile);
                    DateTime dateTime = DateTime.UtcNow.Date;
                    aBill.DateTime = dateTime.ToString("MM/dd/yyyy");
                    //aBill.DateTime = DateTime.Now.ToString("MM/dd/yyyy");

                    billSave = aPatientManager.AddBill(aBill);
                }
                if (billSave == "Bill not added")
                {
                    patientMessageLabel.Text = "Not Saved";
                }
                else
                {
                    patientMessageLabel.Text = "Saved";
                    GetBillPDF(aBill.BillNo);
                }
            }
            else
            {
                patientMessageLabel.Text = patientSaved;
            }
            clear();
        }