How to load twitter button asynchronously [closed]

Question

Following Yoast's direction per his post here I am trying to make my twitter's button load asynchronously in order to decrease page load times. Unfortunately, the following code in my functions.php does not work

<div id="twitterbutton">
<a href="http://twitter.com/share" class="twitter-share-button" data-count="horizontal" data-via="tricksdaddy">Tweet</a>
<script type="text/javascript"> jQuery(document).ready(function($) {
  // Load Tweet Button Script
  var e = document.createElement('script');
  e.type="text/javascript"; e.async = true;
  e.src = 'http://platform.twitter.com/widgets.js';
  document.getElementsByTagName('head')[0].appendChild(e);
}
</script></div>

Any hints will be greatly appreciated