Protected Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs)
    ' Lista wszystkich elementw SectionGroups z pliku machine.config
    Dim configSetting As Configuration = _ 
      System.Configuration.ConfigurationManager.OpenMachineConfiguration()
    GridView1.DataSource = configSetting.SectionGroups
    GridView1.DataBind()
End Sub
