Hey guys,
I've recently been developing a C# application for myself and a friend of mine and I've basically managed to code everything except one feature that basically gets the amount of credits that you have on your account from a site called getref.com.

To do this I need to either login the account via a Login URL by means of the WebClient Object in the .Net Framework which would look something like:

Code:
WebClient myClient = new WebClient();

string strRes = myClient.DownloadString("http://ww.getref.com/processlogin.asp?&txtUsername=<username>&txtPassword=<password>&login=Logon");
I can then simply parse the string strRes to find the amount of credits.

I can also try to login via an HttpWebRequest:

Code:
string User = "******";
string Pass = "******";

string url = "http://ww.getref.com/processlogin.asp";
string pdata = "&txtusername=" + User + "&txtpassword=" + Pass + "&login=Logon";

string strRes = SendWebRequest(url, pdata, 8, "");


private static string SendWebRequest(string Url, string PData, int Interval, string Referer)
{
    HttpWebRequest req = (HttpWebRequest)WebRequest.Create(Url);
    if (PData != "")
    {
        req.Method = "POST";
        req.ContentType = "application/x-www-form-urlencoded";
        byte[] arrbytes = Encoding.ASCII.GetBytes(PData);
        req.ContentLength = arrbytes.Length;
        Stream reqStream = req.GetRequestStream();
        reqStream.Write(arrbytes, 0, arrbytes.Length);
        reqStream.Close();
    }
    if (Referer != "")
    {
        req.Referer = Referer;
    }
    req.Timeout = Interval * 0x3e8;
    HttpWebResponse httpresponse = (HttpWebResponse)req.GetResponse();
    StreamReader _streamreader = new StreamReader(httpresponse.GetResponseStream());

    return _streamreader.ReadToEnd().ToString();
}
Just like the other example I can then simply parse the string strRes to find the amount of credits as well.

My problem is that of finding the correct login Url to login or that of creating the right HttpWebRequest for logging in. :/

Does anyone know what I'm doing wrong?
Are my HTTP Headers incorrect?
Am I crafting my query properly?

Sorry if I'm doing a lot of stupid mistakes. I'm very inexperienced when it comes to web dev thats why I decided to ask the pros xD.

Thanks a lot.

Regards,
CSharpGuy.