Nested Grid View Problem

Hi,

I'm having problems returning the text value of a label that is databound in a parent <code>gridview. I need to use the text value to assign it to a select parameter in a child <code>gridview but it keeps throwing a null reference. Can anyone see a problem with the following code?

I have a parent gridview called browsetopicsview, a child gridview called NestedPostCount a databoud label called CreatedBy which is what i want in the where clause of the child select statment.  

 Protected Sub BrowseTopicsView_RowDataBound(ByVal sender As Object, 
               ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) 
                                    Handles BrowseTopicsView.RowDataBound
        Dim s As SqlDataSource = CType(e.Row.FindControl("NestedPostCount"),
                                                                 SqlDataSource)
        Dim g As New Label
        g = CType(FindControl("CreadtedBy"), Label)
        Try
            s.SelectParameters(0).DefaultValue = g.Text
        Catch
            MsgBox("An error has occured in the database,
                         please try again later")
        End Try
End Sub

 Thanks,   

Chris