How to return HTML content from webbrowser control

Hello,

I try to catch the HTML code from a webpage after I have logged in to a page.
HTML is returned but that is the orignal HTML only BEFORE I logged in. For example I try to find "Log out" and other content in the string "getDocumentHTML" returned which exists on the webpage. But that can't be found.

How do we returned the final HTML content for the webpage after logging in?

Thank you!

private void button1_Click(object sender, EventArgs e)
        {
            String url = textBox1.Text;
            webKitBrowser1.Navigate("http://someloginURL.com");
        }
        private void webKitBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            //This doesn't returnd the FINAL HTML content after a login to a webpage
            String getDocumentHTML = webKitBrowser1.DocumentText;
        }