Hi
Here's something else---http://www.sciforums.com/showthread.php?t=71825--

Will pass on more when I find it, if you like and it is helpful to you. Regards!

__________________
Thirty spokes share the wheel's hub; It is the center hole that makes it useful.
Shape clay into a vessel; It is the space within that makes it useful.
Cut doors and windows for a room; It is the holes which make it useful.
Therefore, benefit comes from what is there; Usefulness from what is not there.

Chapter 11 of the Tao