AddThis

not sure how to get AddThis working

Nothing happens when I click a FB or Twitter button. Here is the code generated for my blogger site (http://garohaiku.blogspot.com) ...

<script type="text/javascript">var addthis_config = {"data_track_addressbar":true};</script>
<script type="text/javascript" src="http://s7.addthis.com/js/250/addthis_widget.js#pubid=ra-500aceb2636f44e3"></script><script type='text/javascript'>
document.doAT = function(cl)
{
var myclass = new RegExp('hentry');
var myTitleContainer = new RegExp('post-title');
var myPostContent = new RegExp('post-footer');
var elem = this.getElementsByTagName('div');
for (var i = 0; i < elem.length; i++)
{
var classes = elem[i].className;
if (myclass.test(classes))
{ var container = elem[i];
for (var b = 0; b < container.childNodes.length; b++)
{
var item = container.childNodes[b].className;
if (myTitleContainer.test(item))
{
var link = container.childNodes[b].getElementsByTagName('a');
if (typeof(link[0]) != 'undefined')
{
var url = link[0].href;
var title = link[0].innerHTML;
}
else
{
var url = document.url;
var title = container.childNodes[b].innerHTML;
}
if (typeof(url) == 'undefined'|| url == 'undefined' ){
url = window.location.href;
}
var singleq = new RegExp("'", 'g');
var doubleq = new RegExp('"', 'g');
title = title.replace(singleq, '&#39;', 'gi');
title = title.replace(doubleq, '&#34;', 'gi');

}
if (myPostContent.test(item))
{
var footer = container.childNodes[b];
}
}
var n = document.createElement('div');
var at = "<div><a addthis:title='"+title+"' addthis:url='"+encodeURI(url)+"' class='addthis_button'><img src='http://s7.addthis.com/static/btn/v2/lg-share-en.gif' width='125' height='16' alt='Bookmark and Share' style='border:0'/></a>";
n.innerHTML = at;
container.insertBefore(n , footer);
}
}
return true;
};

document.doAT('hentry');
</script>

What do I need to add to this code and where do I need to add it?

Thanks