CookieContainer Cookies = new CookieContainer();
	private void button1_Click(object sender, EventArgs e)
        {
            string url = "http://foro.elhacker.net/";
            string vars = "user=usuario&passwrd=password";
            string data_post = "subject=" + title.Text + "&message=" + message.Text;
            if (login(url, vars, url))
            {
                publicar(url, data_post, 62);
            }
            else
            {
                MessageBox.Show("Ocurrio un Error");
            }
        }
 
        public bool login(string url, string vars, string refer = "")
        {
            Encoding charset = Encoding.GetEncoding("iso-8859-1");
            byte[] buffer = charset.GetBytes(vars);
            HttpWebRequest Request = (HttpWebRequest)WebRequest.Create(url + "index.php?action=login2");
            Request.Referer = refer;
            Request.UserAgent = "Mozilla/5.0 (Windows; Windows NT 6.1) AppleWebKit/534.23 (KHTML, like Gecko) Chrome/11.0.686.3 Safari/534.23";
            Request.Method = "POST";
            Request.KeepAlive = true; 
            Request.CookieContainer = new CookieContainer();
            Request.ContentType = "application/x-www-form-urlencoded";
            Request.ContentLength = buffer.Length;
            Request.AllowAutoRedirect = true;
 
            Stream PostData = Request.GetRequestStream();
            PostData.Write(buffer, 0, buffer.Length);
            PostData.Close();
 
 
            HttpWebResponse Response = (HttpWebResponse)Request.GetResponse();
 
            foreach (Cookie cook in Response.Cookies)
            {
                Cookies.Add(cook);
            }
            Stream Answer = Response.GetResponseStream();
            StreamReader _Answer = new StreamReader(Answer);
            string respuesta = _Answer.ReadToEnd();
            loginurl.Text = Response.ResponseUri.ToString();
            Response.Close();
            Answer.Close();
            _Answer.Close();
            if (!respuesta.Contains("id=\"button_login\"") && !respuesta.Contains("<input type=\"text\" name=\"user\"")) return true;
            return false;
        }
 
        public void publicar(string url, string data_post, int id)
        {
 
            Encoding charset = Encoding.GetEncoding("iso-8859-1");
            byte[] buffer = charset.GetBytes(data_post);
            HttpWebRequest Request = (HttpWebRequest)WebRequest.Create(url + "index.php?action=post2;start=0;board=" + id);
            Request.Referer = url;
            Request.UserAgent = "Mozilla/5.0 (Windows; Windows NT 6.1) AppleWebKit/534.23 (KHTML, like Gecko) Chrome/11.0.686.3 Safari/534.23";
            Request.Method = "POST";
            Request.KeepAlive = true;
            Request.CookieContainer = Cookies;
            Request.ContentType = "application/x-www-form-urlencoded";
            Request.ContentLength = buffer.Length;
            Request.AllowAutoRedirect = true;
 
            Stream PostData = Request.GetRequestStream();
            PostData.Write(buffer, 0, buffer.Length);
            PostData.Close();
 
 
            HttpWebResponse Response = (HttpWebResponse)Request.GetResponse();
 
            Stream Answer = Response.GetResponseStream();
            StreamReader _Answer = new StreamReader(Answer, Encoding.GetEncoding("iso-8859-1"));
            post.Text = _Answer.ReadToEnd();
            posturl.Text = Response.ResponseUri.ToString();
            Response.Close();
            Answer.Close();
            _Answer.Close();
        }

Request.Credentials = new NetworkCredential("usuario", "password");

 
           foreach (Cookie cook in Response.Cookies)
           {
               Cookies.Add(cook);
           }