Sub reports

How can we create mulitple sub reports in a single parent report , i have to create a detailed audit report. i m trying to do it with single dataset populating with mulitple select commands here is the snippet m trying

void SubreportProcessingEventHandler(object sender, SubreportProcessingEventArgs e)
        {
                ReportDataSet  RD = new ReportDataSet();
               
                 switch (SwitchSubReport)
                 {
                     case 1:
                         {

                             
                             e.DataSources.Add(new ReportDataSource("ReportDataSet_SubReportAuditor", RD.Tables["SubReportAuditor"]));
                             objAdapter.Fill(RD);
                             //SwitchSubReport = 2;
                             break;
                         }
                     case 2:
                         {
                             
                             BindingSource CheckListBS = new BindingSource(RD, "SubReportCheckList");

                             e.DataSources.Add(new ReportDataSource("ReportDataSet_SubReportCheckList", CheckListBS ));  
                             
                             objAdapter.Fill(RD);
                             break;
                         }
                 }
                
 

        }

The problem is that report is showing one sub report at a time . and the 2nd subreport displays report cannot be shown please help me !