Invalid index. (Exception from HRESULT: 0x8002000B (DISP_E_BADINDEX))

Invalid index. (Exception from HRESULT: 0x8002000B (DISP_E_BADINDEX)) (rpt.SetParameterValue("@F_DATE", "Test"))

Imports System.IO
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.HttpApplication
Imports CrystalDecisions.CrystalReports.Engine
Imports CrystalDecisions.Shared
Imports CrystalDecisions.Web
Imports CrystalDecisions.ReportSource
Partial Class Reportviewer
    Inherits System.Web.UI.Page
    Public str As String
    Public rptname As String
    Public sf As String
    Private rpt1 As CrystalDecisions.CrystalReports.Engine.ReportDocument

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim con As New ConnectionInfo
        Dim con1 As New ConnectionInfo
        Dim db1 As Database
        Dim dbs As Tables
        Dim db As Table
        Dim tab As TableLogOnInfo
        rptname = Session("rptname") 
        If rptname = "" Then
            Exit Sub
        End If
        str = Convert.ToString(Session("Str")) '" {INV_HEAD.HInv_NO}='0000000001' "
        Dim rpt As New CrystalDecisions.CrystalReports.Engine.ReportDocument
        With con
            .UserID = "sa"
            .Password = "sa"
            .DatabaseName = "tes"
            ' .ServerName = "Develope-PC"
            .ServerName = "server"
        End With
        rpt.Load(Server.MapPath("..\Report\INV_LIST1.rpt"))
      
        db1 = rpt.Database
        dbs = db1.Tables
        For Each db In dbs
            tab = db.LogOnInfo
            tab.ConnectionInfo = con
            db.ApplyLogOnInfo(tab)
        Next
          CrystalReportViewer1.SelectionFormula = str
    CrystalReportViewer1.ReportSource = rpt
'''''''''''''''''''''''''''

'this is my error line 
rpt.SetParameterValue("@F_DATE", "Test")


'''''''''''''''''''''
     CrystalReportViewer1.ShowFirstPage()
    CrystalReportViewer1.RefreshReport()

    End Sub
End Class

Server Error in '/e-Tasheel' Application.

Invalid index. (Exception from HRESULT: 0x8002000B (DISP_E_BADINDEX))

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.Runtime.InteropServices.COMException: Invalid index. (Exception from HRESULT: 0x8002000B (DISP_E_BADINDEX))

Source Error: 


Line 15:         crParameterDiscreteValue.Value = "@F_DATE"
Line 16:         crParameterFieldDefinitions =  cryRpt.DataDefinition.ParameterFields()
Line 17:         crParameterFieldDefinition = crParameterFieldDefinitions.Item("@F_DATE")
Line 18:         crParameterValues = crParameterFieldDefinition.CurrentValues
Line 19: 

Source File: C:\Users\surya\Desktop\Amjidh\e-Tasheel\Report\Default.aspx.vb    Line: 17 

Stack Trace: 


[COMException (0x8002000b): Invalid index. (Exception from HRESULT: 0x8002000B (DISP_E_BADINDEX))]
   CrystalDecisions.ReportAppServer.DataDefModel.FieldsClass.get_Item(Int32 Index) +0
   CrystalDecisions.CrystalReports.Engine.ParameterFieldDefinitions.get_Item(Int32 index) +81
   CrystalDecisions.CrystalReports.Engine.ParameterFieldDefinitions.get_Item(String fieldName) +105
   Report_Default.Page_Load(Object sender, EventArgs e) in C:\Users\surya\Desktop\Amjidh\e-Tasheel\Report\Default.aspx.vb:17
   System.Web.UI.Control.OnLoad(EventArgs e) +91
   System.Web.UI.Control.LoadRecursive() +74
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2207

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1