FormPanel submit response as json format

[venu]

I am using GWT+GXT and JSon format.

I am submitting the FormPanel and i want to get the response from server as json format.
I added a listener to the formpanel but the FormEvent.resultHtml is coming as null.

When i see it in firebug, the response is shown as :
{"message":"Diagnosis Successfully created","success":true}

How to get this string in FormEvent resultHtml field ?

Code Snippet:

form.addListener(Events.Submit, new Listener<FormEvent>() {
public void handleEvent(FormEvent arg0) {
GWT.log("Result ::"+arg0.resultHtml, null);
}
});

Can anyone help me in solving this problem?
If there is any alternate way to handle this, let me know.

thx.

[sven]

You have to submit to the same domain as the hole page is running, as else you are not able to access the iframe. This is a secrurity restriction in browsers.

[armandoxxx]

this works for me !

settingsForm.addListener(Events.Submit, new Listener<FormEvent>() {
            public void handleEvent(FormEvent be) {

                String response        = be.resultHtml;
                if(response.indexOf("<pre>") != -1) {
                    response = response.substring(5, response.length()-6);
                }
                JSONValue rspValue     = JSONParser.parse(response);
                JSONObject rspObj    = rspValue.isObject();
                Window.alert(rspObj.get("message").toString());
                
            }
        });