private void FrmXtraSalaryPostedVoucher_Load(object sender, EventArgs e)
        {
            salaryVouchersPresenter.Display(PostedDate.ToShortDateString());
            if (gridViewSalaryVoucher.RowCount > 0)
            {
                RefNo = gridViewSalaryVoucher.GetRowCellValue(0, "RefNo").ToString();
                employeesPresenter.DisplayByMonthDateAndRefNo(PostedDate.ToShortDateString(), RefNo);
            }

            if (RefNo == "" || RefNo == null)
            {
                btnPostedVoucher.Enabled = false;
                btnCancelCalc.Enabled    = false;
            }
        }