public static WPF_GUI showMessage(this WPF_GUI wpf_Gui, WinForms.WebBrowser browser, string title, string message, string url)
        {
            O2Thread.mtaThread(
                () => {
                var htmlMessage = ("<html><body cellspacing=\"0\" cellpadding=\"0\"><font face=Arial><center>".line() +
                                   "   <h2>{1}</h2>".line() +
                                   "   <h3>{2}</h3>".line() +
                                   "   <img src=\"{0}\"/>" +
                                   "</center>".line() +
                                   ((url).valid()
                                                                                        ? "<div style=\"position:absolute; bottom:0px;width:100%;font-size:xx-small;\"><center>showing help page: <a href=\"{3}\"target=blank>{3}</a></center></div>".line() +
                                    "<iframe src =\"{3}\" style=\"position:absolute; bottom:15px; height=70%; width:100%;\"/>".line()

                                                                                        : "") +
                                   "</font></body></html>")
                                  .format("O2Logo_Small.gif".local(), title, message, url);
                browser.set_Text(htmlMessage);
            });
            return(wpf_Gui);
        }