there is no error but it never show the report

Question

my source is

<CR:CrystalReportViewer ID="CrystalReportViewer1" runat="server"

AutoDataBind="True" DisplayPage="False" ReportSourceID="CrystalReportSource2"

Width="500px" BestFitPage="False" Height="800px" />

<CR:CrystalReportSource ID="CrystalReportSource2" runat="server">

<Report FileName="Cashvoucher.rpt">

</Report>

</CR:CrystalReportSource>

 

my code is

 

ReportDocument reportdocument = new ReportDocument();

string iid = Request.QueryString["id"].ToString();

ParameterFields paramFields = new ParameterFields();

ParameterField paramField = new ParameterField();

ParameterDiscreteValue paramDiscreteValue = new ParameterDiscreteValue();

paramField.Name = "id";

paramDiscreteValue.Value = iid;

paramField.CurrentValues.Add(paramDiscreteValue);

paramFields.Add(paramField);

CrystalReportViewer1.ParameterFieldInfo = paramFields;

reportdocument.Load(Server.MapPath("Cashvoucher.rpt"));

reportdocument.SetParameterValue("id", iid);

// string str = "select id,Name,Section,Details,advance from salary where id='" + iid + "'";

string str = "select Name,daysinmonth,presentdays from salary where id='" + iid + "'";

DataSet ds = mvl.GETDS(str);

reportdocument.SetDataSource(ds.Tables[0]);

CrystalReportViewer1.ReportSource = reportdocument;

//CrystalReportViewer1.RefreshReport();

}