C# Login to web site
===

I try to login to http://www.argusmedia.com/pages/SignIn.aspx using C#.
But I can't find out names of form's parameters (Email and Password) which I have to POST with my WebRequest. Is it ctl00$P$SignIn$LoginForm$UserName and ctl00$P$SignIn$LoginForm$Password ?

    string formUrl = "http://www.argusmedia.com/pages/SignIn.aspx";
    string formParams = string.Format("ctl00$P$SignIn$LoginForm$UserName={0}&ctl00$P$SignIn$LoginForm$Password={1}", mylogin, mypassword);
    string cookieHeader;
    WebRequest req = WebRequest.Create(formUrl);
    req.ContentType = "application/x-www-form-urlencoded";
    req.Method = "POST";
    byte[] bytes = Encoding.ASCII.GetBytes(formParams);
    req.ContentLength = bytes.Length;
    using (Stream os = req.GetRequestStream())
    {
        os.Write(bytes, 0, bytes.Length);
    }
    WebResponse resp = req.GetResponse();
    cookieHeader = resp.Headers["Set-cookie"];

    string pageSource;
    using (StreamReader sr = new StreamReader(resp.GetResponseStream()))
    {
        pageSource = sr.ReadToEnd();
    }

But I can't login. Guess that I post wrong parameters.