unable to display data from sub report

Hi,

anyone could help me to solve why sub report is not showing data

I create a sub report and feed data to datasource of crystal report by vb.net statement

vb.net code

Dim dtavg2 As New DataTable

dtavg2.Columns.Add("BM", Type.GetType("System.Double"))

dtavg2.Columns.Add("DP", Type.GetType("System.Double"))

dr = dtavg2.NewRow

dr.Item("BM") = 0

dr.Item("DP") = 1

dtavg2.Rows.Add(dr)

rpt.Subreports("rptDailyBookingAvg2.rpt").SetDataSource(dtavg2)

The data are general by vb.net coding to testing.

After feed to data to subreport, there is not data showing,

somebody could help me?

Thank you