Check login is success or not on twitter with webbrowser

See more:

C#

WebBrowserControl

twitter

Hello i want to make a control like this. I'am taking twitter ID and Password from user. via textBox and when i pressed "check" button webBrowser puts them to the twitter's form controls. SO i login. But when i write wrong ID or Password , i want to sent a message to user like "Wrong ID or Password" thanks for your helps.

When i press button timer control starts. Here is my timer1_Tick event.

private void timer1_Tick(object sender, EventArgs e)
        {
            webBrowser1.Document.GetElementById("signin-email").SetAttribute("value", "exampleID");
            webBrowser1.Document.GetElementById("signin-password").SetAttribute("value","examplePASSWORD");
            foreach (HtmlElement el in webBrowser1.Document.GetElementsByTagName("button"))
            {

                if (el.GetAttribute("className") == "submit btn primary-btn flex-table-btn js-submit") // i found button control with this
                {
                     el.InvokeMember("click"); // click to button
                    /*if (success) // control .. here is my problem
                      { 
                      timer1.Stop();
                      mbox("success login");
                      }
                    else
                    {
                    timer1.Stop();
                    mbox("login failed");
                    }
                    */
                    break;
                }
                
            }
        }