title: Jquery animate attribute?
body: <p>I use something like this, for auto growing (auto size) textarea:</p>
  
  <pre><code>$('textarea').keyup(function() {
      $(this).attr('rows', $(this).val().split("\n").length);
  });
  </code></pre>
  
  <p>How to add smooth animation to auto growing for code above? </p>
  
  <p>Function <code>.animate()</code> with <code>rows</code> doesn't work.</p>