else if (sel.equals("System.err"))
        out = System.err;
      Object simStatus = app.find(myUi, "simStatus");
      try {
        ScriptableObject scope = cx.initStandardObjects();
        cx.evaluateString(scope, script, "<cmd>", 1, null);
        if (similarity != null) similarity.destroy();
        similarity = new CustomSimilarity(cx, scope, out);
        app.setCustomSimilarity(similarity);
        app.setString(simStatus, "text", "OK");
        app.setColor(simStatus, "foreground", Color.green);