C#

static void Main(string[] args)
{
    string url = "https://scgi.ebay.com/ws/eBayISAPI.dll?RegisterEnterInfo";
    string method = "POST";
    string postdata = "firstname=Test&lastname=Tester&address1=teststreet+20&zip=56683&st_ct=Tenstrike%2C+MN&countryid=1&email=secret1234%40walla.co.il&retype_email=secret1234d%40walla.co.il&dayphone1=789&dayphone2=678&dayphone3=6786&userid=secretrotd442017771&pass=Qq123456&rpass=Qq123456&canned=4&myanswer=Paffi&birthdate2=2&birthdate1=17&birthdate3=1976&frmaction=submit&mode=1&country=&MfcISAPICommand=RegisterEnterInfoV4&city=Tenstrike&state=MN&isSug=true";
    string file = sendRequest(url, method, postdata);

    // write a line of text to the file
    TextWriter tw = new StreamWriter("C:\\WebPost_Response.htm");
    tw.WriteLine(file);
    // close the stream
    tw.Close();
}
public static string sendRequest(string url, string method, string postdata)
{
    WebRequest rqst = HttpWebRequest.Create(url);
    rqst.Method = method;
    if (!String.IsNullOrEmpty(postdata))
    {
        rqst.ContentType = "application/xml";
        rqst.ContentType = "application/x-www-form-urlencoded";
        byte[] byteData = UTF8Encoding.UTF8.GetBytes(postdata);

        rqst.ContentLength = byteData.Length;
        using (Stream postStream = rqst.GetRequestStream())
        {
            postStream.Write(byteData, 0, byteData.Length);
            postStream.Close();
        }
        ((HttpWebRequest)rqst).KeepAlive = false;
        StreamReader rsps = new StreamReader(rqst.GetResponse().GetResponseStream());
        string strRsps = rsps.ReadToEnd();
        return strRsps;
    }
    else
    {
        return "Failed";
    }
}