Crystal Report Viewer does not show detail of report

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C#

CrystalReports

I am using Crystal Report 10, with visual studio 2010, the report viewer shows only the group section, when i click on any group, it shows me an error of "
No valid report source is available."
Method in Class is :

public static object ConnectionForReports(ReportDocument objReport)
        {
            SqlConnection cn = null;
            cn = new SqlConnection(Properties.Settings.Default.CMScon);
            CrystalDecisions.Shared.TableLogOnInfo logOnInfo = null;
            logOnInfo = objReport.Database.Tables[0].LogOnInfo;
            
            logOnInfo.ConnectionInfo.ServerName = cn.DataSource;
            logOnInfo.ConnectionInfo.DatabaseName = cn.Database;
            logOnInfo.ConnectionInfo.UserID = "sa";
            logOnInfo.ConnectionInfo.Password = "********";
            objReport.Database.Tables[0].ApplyLogOnInfo(logOnInfo);
            return objReport;
        }
And the code behind is:

protected void CmdPreview_Click(object sender, ImageClickEventArgs e)
        {
                InquiryReports objReport = new InquiryReports();
                string vSelectionFormula = null;
                ReportDocument objReports = (ReportDocument)MethodClass.ConnectionForReports(objReport);
                vSelectionFormula = "{CompalintView.ComplaintStatus}='" + CboCompStatus.Text + "'";
                InquiryRptViewer.SelectionFormula = vSelectionFormula;
                InquiryRptViewer.ReportSource = objReports;
            }