Failure to do persistent connection

Hi,

I'm implementing a program to connect a site and walk through
the first few pages. To do this I choose my.yahoo.com as my
target, and start to implement as follows:

I use a URL instance to connect to "http: file://my.yahoo.com" url.
It responses with a single cookie header as:

  Set-Cookie: B=somevalue; expires=date; path=/ ; domain=.yahoo.com;

My program parses this cookie and prepare the following string
to return back in the next POST request:

  Cookie: $version=0; B=somevalue; $path=/; $domain=.yahoo.com
  (The 'B=samoevalue' format is tested too)
  
The program will attach a parameter list for logging in to
MyYahoo in the following format:

  param1=value1&param2=value2&...

(The parameters list is complete and all parameters name are
spelled correctly), but the server will response with a new
cookie and send a page that contains a message which says "An
Error Occurred Setting Your User Cookie".

I tried every thing I guessed, but no success. I don't know
what is the problem. The last tested code is attached bellow.

Thank you in advance for your kind attentions.
@liz@

---------------------------------------

 System.getProperties().put( "proxySet",  "true" );
 System.getProperties().put( "proxyHost", "128.1.1.1" );
 System.getProperties().put( "proxyPort", "80" );
 
 URL url = new URL("http://my.yahoo.com");
 HttpURLConnection connection = (HttpURLConnection)url.openConnection();
   
 connection.setRequestMethod("GET");
 connection.setRequestProperty("Connection", "Keep-Alive");
 connection.setRequestProperty("Proxy-Connection", "Keep-Alive");
 connection.setRequestProperty("Cashe-Control", "no-cashe");
 connection.setDoOutput(true);
 connection.setUseCaches(false);
 Object content = connection.getContent();
   
 Cookie cookie = null;
 int    index  = 0;
 String header = connection.getHeaderField(index);
 String key    = connection.getHeaderFieldKey(index);
  
 StringBuffer cookieStr = new StringBuffer("");
   
 while (header != null) {
  if ("Set-Cookie".equalsIgnoreCase(key)) {
   // parses the cookie header
   cookie = parseCookie(header);
   if (cookieStr.length() > 0) {
    cookieStr.append(",");
   }
   // converts the cookie to this format:
   //    $version=1; name=value; $path=path; $domain=domain
   cookieStr.append(toRFC_2109(cookie));
  }
    
  index++;
  header = connection.getHeaderField(index);
  key    = connection.getHeaderFieldKey(index);
    
 }

 BufferedInputStream in = (BufferedInputStream)content;
 OutputStream out = new FileOutputStream(args[0]);
 int c;
 while ((c=in.read())>= 0){
  out.write((char)c);
 }
 out.close();
   
  
 url = new URL("http://login.yahoo.com/config/login");
 connection = (HttpURLConnection)url.openConnection();
   
 SimpleDateFormat formatter = new SimpleDateFormat ("EEE, dd MMM yyyy HH:mm:ss 'GMT'");
 Date now = new Date();
 String dateStr = formatter.format(now);
 System.out.println("Date=<" + dateStr + ">");
   
 connection.setRequestMethod("POST");
 connection.setRequestProperty("Cashe-Control", "no-cashe");
 connection.setRequestProperty("Connection", "Keep-Alive");
 connection.setRequestProperty("Proxy-Connection", "Keep-Alive");
 connection.setRequestProperty("Date", dateStr);
 connection.setDoOutput(true);
 connection.setUseCaches(false);
   
   
 if ( ! "".equals(cookieStr)) {
  connection.setRequestProperty("Cookie", cookieStr.toString());
 }

 String params = URLEncoder.encode(".tries")      + "=" + URLEncoder.encode("1")  + "&" + 
   URLEncoder.encode(".done")       + "=" + URLEncoder.encode("http://my.yahoo.com") + "&" +
   URLEncoder.encode(".src")        + "=" + URLEncoder.encode("my") + "&" +
   //... other parames
   

 connection.setRequestProperty("Content-Length", Integer.toString(params.length()));
 DataOutputStream o = new DataOutputStream(connection.getOutputStream());

 o.writeBytes(params);
 o.flush();
 o.close();
   
 content = connection.getContent();
   
 in = (BufferedInputStream)content;
 out = new FileOutputStream(args[1]);
 while ((c=in.read())>= 0){
  out.write((char)c);
 }
 out.close();
   
 System.out.println();