/// <summary>
 /// Function to use CashOrParty Combofill
 /// </summary>
 public void DueDays()
 {
     try
     {
         SalesOrderBll bllSalesOrder = new SalesOrderBll();
         txtDueDays.Text = bllSalesOrder.DueDays(dtpDate.Value, dtpDueDate.Value).ToString();
     }
     catch (Exception ex)
     {
         MessageBox.Show("SO20:" + ex.Message, "OpenMiracle", MessageBoxButtons.OK, MessageBoxIcon.Information);
     }
 }