[jQuery] how i can access classes in my div?

[Luciano]

how i can access classes in my div?
example:

$("#box1.bloc-top").click(function () {
          $(".bloc-center").slideToggle("slow");
});

$("#box2.bloc-top").click(function () {
          $(".bloc-center").slideToggle("slow");
});

$("#box3.bloc-top").click(function () {
          $(".bloc-center").slideToggle("slow");
});


<div id="box1" class="box">
     <bloc-top>content top</bloc-top>
     <bloc-center>content slideToggle</bloc-center>
</div>

<div id="box2" class="box">
     <bloc-top>content top</bloc-top>
     <bloc-center>content slideToggle</bloc-center>
</div>

etc..
i tryed this it but no success