I have the standard Facebook login button on my homepage and I don't want people to automatically log into my site with their Facebook account, only if the user clicks the login button.

If the user is not logged in Facebook, a popup will appear asking him his credentials and he will be redirected to `loggedin.html` after that.

```
<div id="fb-root"></div>
<fb:login-button perms="email"></fb:login-button>

<script>
    window.fbAsyncInit = function() {
        FB.init({
            appId  : 'xxxxxxxxxxxx',
            status : true,
            cookie : true,
            xfbml  : true
        });

        FB.Event.subscribe('auth.login', function() {
            window.location = "loggedin.html";
        });
    };

    (function() {
        var e = document.createElement('script');
        e.src = document.location.protocol + '//connect.facebook.net/en_US/all.js';
        e.async = true;
        document.getElementById('fb-root').appendChild(e);
    }());
</script>

```

If the user is already logged in Facebook, when he clicks the button the popup appear and disappear right away, I am OK with that. But the user is not redirected to `loggedin.html`. How can I do that ?