function input_onclick() {
    var input_geaendert = document.getElementById("opliste_geaendert");
    input_geaendert.value = "ist_geaendert";
}

If Not OPListenBrowser.Document Is Nothing Then
    If Not OPListenBrowser.Document.GetElementById("wkz_identnr") Is Nothing _
      Then
 
        Dim wkz_identnrHtml As HtmlElement = _
                 OPListenBrowser.Document.GetElementById("wkz_identnr")
 
        Dim identNr As String = wkz_identnrHtml.OuterHtml.Split("=")(2)

Grüße Andi