; $Id: INSTALL.TXT,v 1.1.2.2 2010-06-24 12:18:40 rsevero Exp $

You need to download Bluff files from: 
http://bluff.jcoglan.com/

Bluff contains all necessary JavaScript files for drawing charts.
You need to extract downloaded archive and copy following files:

bluff-min.js
excanvas.js
js-class.js

and place them in the "bluff" folder of the module.