Facebook Like Box / -Button: React to click

I'm creating a facebook app that should show content only to fans of a certain page. I can easily get the info whether the user is a fan of the page or not using FQL and want to display a Like Box or a Like Button if the user is not already a fan. After the user clicked onto Like, I'd like to display the content that is visible for fans only.

So here's my question: Is it possible to react when the user clicks "Like"? I've tried onclick, but it didn't work.

Here's the code of my Like Box:

<div class="fb-like-box" data-href="https://www.facebook.com/myFanPage" data-colorscheme="light" data-show-faces="false" data-header="false" data-stream="false" data-show-border="false" onclick="alert('TEST');"></div>

And the one for the Like Button:

<div class="fb-like" data-href="https://www.facebook.com/myFanPage" data-layout="standard" data-action="like" data-show-faces="true" data-share="false" onclick="alert('TEST2');"></div>

Thanks very much!

Yes, possible using FB.Event.subscribe() and XFBML

HTML:

<fb:like href="{Herf}" width="450"></fb:like>

JS:

window.fbAsyncInit = function() {
    FB.init({
        appId: '{appID}',
        status: true,
        xfbml: true
    });

    // FB event listener 
    FB.Event.subscribe('edge.create', function (url) {
     console.log('You liked the URL: ' + url);
    });
};

DEMO