问jquery宽度为0

EN

<div class="entity" id="id-@user.id">
   <div class="inactive">
      <div class="touch-header">                                               
         <div>
            <small>@user.name<br>@user.surname</small>
         </div>

         <div role="button" data-toggle="modal" id="home_office_id-@user.id" class="home_office_log pull-right" style="margin-top: -2.2%;text-align:center; margin-right: 2px;opacity: 0.8;width: 50px; height: 50px;position: absolute; margin-left: 4.9%;z-index: 1;">
           ...
         </div>
      </div>
   </div>
</div>

var lab = $('div.entity#id-' + userId).children().
        children().children().children('small');                         
lab.css('position', 'relative').animate({
    left: $('.entity#id-'+userId).width() - lab.width() / 2 - 15
}, 500);