Adding The 'Add This' Code To Posts

Hello,
I’m currently building a site called http://www.johnoshea.com/ and I’m trying to insert the ‘Add This’ code at the bottom of my posts so they appear both on the main page and in individual posts.

Can someone please tell me where I should place the code?

<!-- AddThis Button BEGIN -->
<div class="addthis_toolbox addthis_default_style ">
<a></a>
<a></a>
<a></a>
<a></a>
</div>
<script type="text/javascript">var addthis_config = {"data_track_clickback":true};</script>
<script type="text/javascript" src="http://s7.addthis.com/js/250/addthis_widget.js#pubid=ra-4r4515r6586784abaa"></script>
<!-- AddThis Button END -->

At the moment I’ve got it placed badly at the bottom but I’ve installed the “Share This” plugin which appears exactly where I want my ‘Add This’ widget to appear.

Thanks