FB.Event.subscribe object return

I would like to know what is the structure of the object the function FB.开发者_开发问答Event.subscribe return when i use the following code:

FB.Event.subscribe('comment.create', function(response) {
    alert("Thank you for leaving a comment! :)");
});

thanks in advance :D

You can use

alert (JSON.stringify(response));

to get the full response. That works for any object, actually.

I tend to use console.log(response) to have a look at the object, I find that an alert box is insufficient for large objects. (I use facebook with the firebug extension installed)