private bool SaveInvoice(ref string ErrorMessage)
 {
     try
     {
         CI   invoice = CreateInvoiceObject();
         bool IsSave  = invoice.Save(ref ErrorMessage);
         if (IsSave)
         {
             InvoiceNo = invoice.InvoiceNo;
         }
         return(IsSave);
     }
     catch (Exception ex)
     {
         throw ex;
     }
 }