printing on demand Subreport crystal

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i add a print button to print the report and the on demand Subreport crystal

i try this code in the button
crReportDocumentForex.PrintToPrinter(1, False, 1, 99)
but it print the main report regardless the viewer view the main or the
subreport .
and i try
crReportDocumentForex.OpenSubreport("Details").PrintToPrinter(1, True, 1, 11)

but it print the subreport without any data regardless the viewer view the
main or the subreport .

I need to print the subreport with data and to know which report is viewer
(main or sub )