' Show how to set LockItem
' It adds a new UrlConfigElement to 
' the collection.
Shared Sub LockItem()
    Dim name As String = "Contoso"
    Dim url As String = "http://www.contoso.com/"
    Dim port As Integer = 8080

    Try
        ' Get the current configuration file.
        Dim config _
        As System.Configuration.Configuration = _
        ConfigurationManager.OpenExeConfiguration( _
        ConfigurationUserLevel.None)

        ' Get the MyUrls section.
        Dim myUrls As UrlsSection = _
        config.Sections("MyUrls")


        ' Create the new  element.
        Dim newElement _
        As New UrlConfigElement(name, url, port)

        ' Set its lock.
        newElement.LockItem = True

        ' Save the new element to the 
        ' configuration file.
        If Not myUrls.ElementInformation.IsLocked Then

            myUrls.Urls.Add(newElement)

            config.Save(ConfigurationSaveMode.Full)

            ' This is used to obsolete the cached 
            ' section and read the updared version 
            ' from the configuration file.
            ConfigurationManager.RefreshSection("MyUrls")
        Else
            Console.WriteLine("Section was locked, could not update.")
        End If

    Catch e As ConfigurationErrorsException
        Console.WriteLine("[LockItem: {0}]", _
        e.ToString())
    End Try

End Sub