<a href="/rating/up/2" data-rel="rating">UP</a>

<script>
$(document).on('click', '[data-rel="rating"]', function {
    $.post($(this).prop('href'), function(data) {
         alert('posted!!!');
    });
});
</script>

<a href="/rating/up/2" data-rel="rating">UP</a>

<script>
$(document).on('click', '[data-rel="rating"]', function(e) {
    e.preventDefault();
    $.post($(this).prop('href'), function(data) {
         alert('posted!!!');
    });
    return false;
});
</script>