passing date parameters into crystal report

[potatochips]

hi..
can anybody help me in passing date parameters into crystal report?
i wanna do something like the user types in the date and clicks on OK button to view the crystal report according to the date typed by the user..

below is my codings..
but there's this error "Invalid index. (Exception from HRESULT: 0x8002000B (DISP_E_BADINDEX)"
at the bolded lines below..

Private Sub btn_ok_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_ok.Click

        Dim cryRpt As New ReportDocument
        cryRpt.Load("C:\CrystalReport3.rpt")

        Dim crParameterFieldDefinitions As ParameterFieldDefinitions
        Dim crParameterFieldDefinition As ParameterFieldDefinition
        Dim crParameterValues As New ParameterValues
        Dim crParameterDiscreteValue As New ParameterDiscreteValue

        crParameterDiscreteValue.Value = TextBox1.Text
        crParameterFieldDefinitions = _
   cryRpt.DataDefinition.ParameterFields
        [B]crParameterFieldDefinition = _
   crParameterFieldDefinitions.Item("DealDate")[/B]
        crParameterValues = crParameterFieldDefinition.CurrentValues

        crParameterValues.Clear()
        crParameterValues.Add(crParameterDiscreteValue)
        crParameterFieldDefinition.ApplyCurrentValues(crParameterValues)

        TestReport.CrystalReportViewer1.ReportSource = cryRpt
        TestReport.CrystalReportViewer1.Refresh()

    End Sub

:)
thanks alot...