Export web Crystal Reports XI to Excel

How to export web Crystal Reports XI to Excel? The export option of Excel doesn't show up on my web Crystal Report. My code is as follows :

String reportName = "1308_001.rpt";
Object reportSource = new Object();
//---------- Create a ReportClientDocument ----------
ReportClientDocument oReportClientDocument = new ReportClientDocument();
//Open report.
oReportClientDocument.open(reportName, 0);
//Get the report source
reportSource = oReportClientDocument.getReportSource();
//create the CrystalReportViewer object
CrystalReportViewer oCrystalReportViewer = new CrystalReportViewer();
//set the reportsource property of the viewer
oCrystalReportViewer.setReportSource(reportSource);
//set viewer attributes
oCrystalReportViewer.setOwnPage(true);
oCrystalReportViewer.setOwnForm(true);
//set the CrystalReportViewer print mode
oCrystalReportViewer.setPrintMode(CrPrintMode.ACTIVEX);
...