Facebook Login issue C#

string email = "email";string pw = "pw";string PostData = String.Format("email={0}&pass={1}", email, pw);




             CookieCollection cookies = new CookieCollection();
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://www.facebook.com"); 
 request.CookieContainer = new CookieContainer();
 request.CookieContainer.Add(cookies);
 //Get the response from the server and save the cookies from the first request..
 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 cookies = response.Cookies;




            string getUrl = "https://www.facebook.com/login.php?login_attempt=1";
 string postData = String.Format("email={0}&pass={1}",  "[email protected]", "yourpassword");
 HttpWebRequest getRequest = (HttpWebRequest)WebRequest.Create(getUrl);
 getRequest.CookieContainer = new CookieContainer();
 getRequest.CookieContainer.Add(cookies); //recover cookies First request
 getRequest.Method = WebRequestMethods.Http.Post;
 getRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.121 Safari/535.2";
 getRequest.AllowWriteStreamBuffering = true;
 getRequest.ProtocolVersion = HttpVersion.Version11;
 getRequest.AllowAutoRedirect = true;
 getRequest.ContentType = "application/x-www-form-urlencoded";




 byte[] byteArray = Encoding.ASCII.GetBytes(postData);
 getRequest.ContentLength = byteArray.Length;   
 Stream newStream = getRequest.GetRequestStream(); //open connection
 newStream.Write(byteArray, 0, byteArray.Length); // Send the data.
 newStream.Close();




 HttpWebResponse getResponse = (HttpWebResponse)getRequest.GetResponse();
 using (StreamReader sr = new StreamReader(getResponse.GetResponseStream()))
 {
   string sourceCode = sr.ReadToEnd();
   webBrowser1.ScriptErrorsSuppressed = true;
   webBrowser1.DocumentText = sourceCode;   
 
 }