how to display multiple lines in one crystal report chart

[michael]

Hi all,

i want to know how to display multiple lines in one crystal report chart in
asp.net

i wrote some codes but it always display 2 lines in separate chart(please
refer to the codes below), how can i display them in one chart? is there any
settings i need to configure?
=============
DataRow row=this.webDS.Line.NewLineRow();
row["grp"]="1";
row["rq"]="11";
row["val"]=10;
this.webDS.Line.Rows.Add(row);

row=this.webDS.Line.NewLineRow();
row["grp"]="1";
row["rq"]="11";
row["val"]=20;
this.webDS.Line.Rows.Add(row);

row=this.webDS.Line.NewLineRow();
row["grp"]="2";
row["rq"]="11";
row["val"]=13;
this.webDS.Line.Rows.Add(row);

row=this.webDS.Line.NewLineRow();
row["grp"]="2";
row["rq"]="11";
row["val"]=17;
this.webDS.Line.Rows.Add(row);

Web.Report.DayLineRpt rpt=new Web.Report.DayLineRpt();
rpt.SetDataSource(this.webDS);
this.ReportLine.ReportSource=rpt;
=============

regards,

benny