webBrowser1.Navigate("http://xxxx.com/wp-login.php");
            webBrowser1.ScriptErrorsSuppressed = true;
            while (webBrowser1.ReadyState != WebBrowserReadyState.Complete) 
                        { 
                            Application.DoEvents(); 
                        }
            webBrowser1.Document.GetElementById("user_login").SetAttribute("value", "admin");
            webBrowser1.Document.GetElementById("user_pass").SetAttribute("value", "123456");
            webBrowser1.Document.GetElementById("wp-submit").InvokeMember("click");