jQuery.addClass not working

Question

This looks valid but it's not working. I'd like the 'huh' div to become opaque when the menu is hovered over. I tried this with fadein/out and it worked but just the once which was odd.

 <script type="text/javascript">
    $( function() {
        $('#menuNav').hover( function() {
            $('#huh').addClass('.opacity');
        }, function(){
            $('#huh').removeClass('.opacity');
        });
    });

</script>

.opacity {
    opacity: 0.3;
}

Answer 1

Use it without dot:

 $(function(){

        $('#menuNav').hover(function(){

            $('#huh').addClass('opacity');
        }, function(){
            $('#huh').removeClass('opacity');
        });
    });