Open id authentication using gwt

[salvin francis]

I have a requirement to build a gwt based application that supports open id based login


I am calling the following code on click of a button in the login page itself

// Encode values for sending as a post request.
String postData = "j_username=" + username 
		+ "&j_password=" + password
		+ ((isRemembered) ? "&_spring_security_remember_me=on" : "");
String serverUrl = URL.encode("j_spring_security_check");

/*
 * Authenticate the user using a request builder to send the request to the server.
 * <p>on successful authentication, open main screen in a pop up
 * */
try
{
    RequestBuilder requestBuilder = new RequestBuilder(RequestBuilder.POST, URL.encode(serverUrl));
    requestBuilder.setHeader("Content-Type", "application/x-www-form-urlencoded");
    requestBuilder.sendRequest(postData, new RequestCallback()
    {
	public void onError(Request request, Throwable exception)
	{
	    //Do nothing
	}

	public void onResponseReceived(Request request, Response response)
	{
	    String responseText = response.getText();
	    int indexStart = responseText.indexOf(startMessageIndicator) + startMessageIndicator.length();
	    int indexEnd = responseText.indexOf(endMessageIndicator);
	    String text = responseText.substring(indexStart, indexEnd);

	    //Login was a success
	    if (text.contains(successMessageIndicator))
	    {
		//Woophie !! code for success comes here.
	    }
	    else if (text.contains(errorMessageIndicator))
	    {
		//Ooops ! get the error message encoded in the page
	    }
	}
    });
}
catch (RequestException e)
{
    //Do nothing
}

Thus as shown, the login page knows of the existence of an error or a success in login itself....

now, i need to port this approach to open id, however open id opens up the referer's url,

How then can I change my system to support this new approach ??