title: jquery .animate is not working
body: <p>i have this jsfiddle :<a href="http://jsfiddle.net/2mRMr/3/" rel="nofollow">http://jsfiddle.net/2mRMr/3/</a></p>
  
  <p>this code is not working :</p>
  
  <pre><code>setInterval(function () {
          box.animate({
              left: function (i, v) { return newv(v, 37, 39); },
              top: function (i, v) { return newv(v, 38, 40); }
          });
  
      }, 20);
  </code></pre>
  
  <p>while this do :</p>
  
  <pre><code>setInterval(function () {
          box.css({
              left: function (i, v) { return newv(v, 37, 39); },
              top: function (i, v) { return newv(v, 38, 40); }
          });
  
      }, 20);
  </code></pre>
  
  <p>any help please  ?</p>