passing a path to crystal report parameter for Picture objec

Question

Hi. I'm trying to pass an image path to a parameter in Crystal Report where I used this parameter to fill in the picture object in the report.

However when I tried to pass the image path to crystal report parameter using c#, I get this error: String reference not set to an instance of a String.

 

Here is my code:

I referenced:

using CrystalDecisions.Web;

using CrystalDecisions.Reporting;

using CrystalDecisions.CrystalReports;

using CrystalDecisions.CrystalReports.Engine;

using CrystalDecisions.Shared;

using System.IO;

 

string qryStr = Request.QueryString["report"].ToString(); //I get the filename based on the querystring of the URL e.g EmployeeNo902706

ReportDocument rpt = new ReportDocument();

string rptPath = "../Reports/SampleReportPicture.rpt";

rpt.Load(Server.MapPath(rptPath));

CrystalDecisions.CrystalReports.Engine.ReportClass clsPic = new CrystalDecisions.CrystalReports.Engine.ReportClass();

clsPic.SetParameterValue(2, "C:\\inetpub\\wwwroot\\ISMPayroll_Reports\\" + qryStr + ".bmp"); --I GET THE ERROR HERE

Page.Response.Clear();

Page.Response.Buffer = true;

MemoryStream os = (MemoryStream)rpt.ExportToStream(CrystalDecisions.Shared.ExportFormatType.PortableDocFormat);

Page.Response.ContentType = "application/pdf";

Page.Response.BinaryWrite(os.ToArray());

Page.Response.End();

rpt.Close();

rpt.Dispose();

 

Can someone help me with this?