Add watermark and disable right-click

Hi,

I’m trying to add a watermark and disable right-click on the website I’m working on, I found this : http://jsfiddle.net/w5gQS/ but I don’t know where to add the JavaScript code :s

I tried adding it in the header.php file of my theme but nothing happened, if anyone knows how would I manage to make it work that would be great !

http://dizzitisgood.com/livre/mike-kelley?ean=9782757206928

http://wordpress.org/plugins/fancybox-for-wordpress/