POST HTTP request from j2me

I am making an HTTP request from a j2me application for CDC. The GET request method woks just fine but when I am using the post method I get the message:

Status Line Code: 413 Status Line Message: Request Entity Too Large

The message that I am sending is only 5 characters long so I don't know which is the problem.

The code is listed bellow.

HttpConnection connection = null;
InputStream inputstream = null;
  try
  {
    connection = (HttpConnection) Connector.open(someURL);
    //HTTP Request
    connection.setRequestMethod(HttpConnection.POST);

    connection.setRequestProperty("User-Agent", "Profile/MIDP-1.0 Configuration/CLDC-1.0");
    connection.setRequestProperty("Content-Language", "zh-tw");
    connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

    if (cookie != null){
        connection.setRequestProperty("cookie", cookie);
    }

    String msg = "u=123";
    connection.setRequestProperty("Content-length", String.valueOf(msg.getBytes().length));
    System.out.println(msg.getBytes().length);
    OutputStream out = connection.openOutputStream();
    out.write(msg.getBytes());
    out.flush();
        // HTTP Response
    System.out.println("Status Line Code: " + connection.getResponseCode());
    System.out.println("Status Line Message: 开发者_开发知识库" + connection.getResponseMessage());
    if (connection.getResponseCode() == HttpConnection.HTTP_OK)
    {
    //some code
    }
  }
  catch(IOException error)
  {
   /*log error*/

  }
  finally
  {
    if (inputstream!= null)
    {
      try
      {
        inputstream.close();
      }
      catch( Exception error)
      {
         /*log error*/

      }
    }
    if (connection != null)
    {
      try
      {
         connection.close();
      }
      catch( Exception error)
      {
         /*log error*/
      }
    }
  }

remove this line

connection.setRequestProperty("Content-length", String.valueOf(msg.getBytes().length));

and try your code again.