Why i m m gwetting wrong results

i m using CR 10 with C#.net in adesktop application. I applied query its results displys on CR Viewer. . According to the query result there must be on;y one result. but i get so many resluts.. plz chkt it .. and let me inform if errir s that i correct it.

here is the code .

ds = con.Select_Query("select CustomerInfo.CName,Reciept.*,WebDevnDes.* from (Reciept INNER JOIN WebDevnDes ON Reciept.RegNo=WebDevnDes.RegNo)INNER JOIN CustomerInfo ON CustomerInfo.RegNo= Reciept.RegNo where Reciept.RecieptNo=" + rcptno);

Reports.WebDevnDes web = new MIS.Reports.WebDevnDes();
                    web.SetDataSource(ds.Tables [0]);
                    crystalReportViewer1.ReportSource = web;
                    crystalReportViewer1.Refresh();