How to export crystal report to excel in .net 2002

Hi All, Advance thanks for ur solutions... I am getting problem while trying to export crystal report(version 9) to excel in .net 2002. Here crystal report is generated basing on 3 parameters. i am trying to export the data while clicking on image button. Here is the code i written: //########### RPT file ########### RPT file is connected to database through UDL connection //######## Page load private void Page_Load(object sender, System.EventArgs e) { if (!IsPostBack) { PrepareReport(); } } // ########### Preparing report by passing parameters private void PrepareReport() { CrystalReportViewer1.Visible = true; sStartDate = "2004-10-11 13:15:39.967" + " 12:00:00 AM"; sEndDate = "2004-10-11 13:23:20.513" + " 12:00:00 AM"; sReportName = "Revenue By Game.rpt"; sTableName = "vwUploadRevenueByGame"; sLocation = "83"; try { oRpt.Load(Server.MapPath(sReportName)); CrystalReportViewer1.ReportSource = oRpt; TableLogOnInfo logOnInfo = new TableLogOnInfo(); logOnInfo = oRpt.Database.Tables[sTableName].LogOnInfo; ConnectionInfo connectionInfo = new ConnectionInfo (); connectionInfo = logOnInfo.ConnectionInfo; connectionInfo.UserID = "sa"; connectionInfo.Password = "sa"; oRpt.Database.Tables [sTableName].ApplyLogOnInfo(logOnInfo); // Removed declaration of Parameters field paramFields = AddParameter("StartDate",sStartDate,paramFields); paramFields = AddParameter("EndDate",sEndDate,paramFields); paramFields = AddParameter("LocationID",sLocation,paramFields); //associate param fields with report CrystalReportViewer1.ParameterFieldInfo = paramFields; // Put user code to initialize the page here //oRpt.Close(); } catch(Exception ex) { lblmsg.Text="Exception Caught:"+ex.Message; } } //################# Adding Parameters ########## public ParameterFields AddParameter(string paramName, string paramValue,ParameterFields paramFields) { ParameterField paramField= new ParameterField (); ParameterDiscreteValue paramDiscreteValue = new ParameterDiscreteValue (); ParameterValues paramValues = new ParameterValues (); // Set the name of the parameter to modify. paramField.ParameterFieldName = paramName; // Set a value to the parameter. paramDiscreteValue.Value = paramValue; paramValues.Add (paramDiscreteValue); paramField.CurrentValues = paramValues; paramFields.Add (paramField); return paramFields; } //########## Export to Excel function ########## // This function is called when image button is clicked private void ExportReport() { try { if (System.IO.File.Exists(Server.MapPath("test1.xls"))) { System.IO.File.Delete(Server.MapPath("test1.xls")); DiskFileDestinationOptions crDiskFileDestinationOptions = new DiskFileDestinationOptions(); ExportOptions crExportOptions = new ExportOptions(); crExportOptions = oRpt.ExportOptions; crDiskFileDestinationOptions.DiskFileName ="test1.xls"; crExportOptions.ExportDestinationType = ExportDestinationType.DiskFile; crExportOptions.ExportFormatType = ExportFormatType.Excel; crExportOptions.DestinationOptions = crDiskFileDestinationOptions; this.oRpt.Export(); lblmsg.Text="Exported to the destination Successfully"; lblmsg.Font.Bold=true; lblmsg.ForeColor = System.Drawing.Color.Green; this.oRpt.Close(); } } catch(Exception ex) { lblmsg.Text=ex.Message; } } //############### Result // We are getting following exception Invalid report file path. if remove isPostback condition, then i am getting following exception Missing parameter field current value