Problem with crystal reports(for oracle)

I used crystal report for c#.net VS 2008 as
report tool with Oracle.
I generate some graphics report but these report
dosent show graph but show data.

example of code which populate DataSet and
generate report

ReportDocument rd;
DataSet ds = new DataSet();
ds.ReadXml(Server.MapPath(“App_Data/XMLFile.xml”
));
ds.Tables[0].TableName = “DTEmployees”;
rd = new ReportDocument();
rd.Load(Server.MapPath(“CREmployees.rpt”));
rd.SetDataSource(ds);
CRVEmployees.ReportSource = rd;
CRVEmployees.DataBind();

how dynamically create chart in my report?
please try to solve my problem