public decimal DueDays(DateTime dtStartDate, DateTime dtEndDate)
 {
     PurchaseOrderMasterSP SPPurchaseOrderMaster = new PurchaseOrderMasterSP();
       decimal decDueDays = 0;
       try
       {
           decDueDays = SPPurchaseOrderMaster.DueDays(dtStartDate, dtEndDate);
       }
       catch (Exception ex)
       {
           MessageBox.Show("PoBll 15:" + ex.Message, "OpenMiracle", MessageBoxButtons.OK, MessageBoxIcon.Information);
       }
       return decDueDays;
 }