public DsReports.SalesInvListDataTable GetSalesReport(string invno = null) { var ta = new DsReportsTableAdapters.taSalesInvList {Connection = {ConnectionString = _constr}}; var ds = new DsReports().SalesInvList; if (invno == null) ta.Fill(ds, false); else { ta.FillBySalesInv(ds, true, false, invno); } return ds; }