水晶报表导出EXCEL格式,怎么写?

Question

//我想将水晶报表以EXCEL格式导出到硬盘上,应该如何写?
        protected void Print_Click(object sender, EventArgs e)
        {
           
                DataTable dt = new DataTable();
                dt =(DataTable )Session ["Report"];
                            EventRt cr = new EventRt();
                cr.SetDataSource(dt);
             //这一句根据不起作用!
                cr.ExportToDisk(CrystalDecisions.Shared.ExportFormatType.ExcelRecord, "c:\\data.xls");
           
                 
            
               
                        
        }