ASP.NET c# Pass Parameter Value to Crystal Report

hi i am new to crystal reports and ASP.NET I have a crystal report and all i want is to pass one parameter to that report via my asp.net page

here is the code that i m using

    protected void setParameterField()
{
    string strReportPath = "\\\\fileserver\\crude Accounting\\reports\\MonthReportNew.rpt";
    string weekReportPath = "\\\\fileserver\\crude Accounting\\reports\\" + "WeekWise.rpt";

    try
    {
        if (!System.IO.File.Exists(strReportPath))
        { throw (new Exception()); }
    }
    catch (Exception ex)
    {
        Response.Write("You Might Not Have Permission To View This Report. Please Contact System Administrator");
        Response.Write(Convert.ToString(ex.Message));
        return;
    }

    //Main Report
    ReportDocument cryRpt = new ReportDocument();
    cryRpt.Load(strReportPath);
    //Sub Report - Week
    ReportDocument weekReport = new ReportDocument();
    weekReport.Load(weekReportPath);

    ParameterFields paramFields = new ParameterFields();
    ParameterField paramField = new ParameterField();
    ParameterDiscrete开发者_如何学JAVAValue paramDiscreteValue = new ParameterDiscreteValue();
    paramField.Name = "@Document_No";
    paramDiscreteValue.Value = "BAD-0511-PRO-2";
    paramField.CurrentValues.Add(paramDiscreteValue);
    paramFields.Add(paramField);

    CrystalReportViewer1.ParameterFieldInfo = paramFields;
   cryRpt.SetParameterValue("@Document_No", "BAD-0511-PRO-2");
    cryRpt.SetDatabaseLogon("myuserid", "mypassword");        
    CrystalReportViewer1.ReportSource = cryRpt;

}

I am continously getting an error missing parameter values i don't know whats wrong with this code.. please help me

You have to pass parameter to your Crystal Report Source. like...

CrystalReportSource1.ReportDocument.SetParameterValue(0, "ParameterValue");