I want to add the Google plus 1 script to my site.

It says to add the first part of the code to the head

<script type="text/javascript" src="http://apis.google.com/js/plusone.js"></script>

The second part of the code is to be added to the body.

<g:plusone></g:plusone>

Can you tell me how and where to add these codes in Zen Cart v1.3.9h

Thank you.