[jQuery] SlideToggle Callback Help

[jQuery] SlideToggle Callback Help


I have this simple slide toggle.
$('.open-post-info').click(function() {
        var id = $(this).attr('id');
        $('.post-info-' + id).slideToggle("medium");
        return false;
});
What I want is when I run the function that after it runs to add CSS
class and when I close/toggle up that the class gets removed. Help
please.