Geri, The info you sent me was exactly what I've been looking for, and it knocked down a brick wall for me (don't worry, I've plenty left to bash myself against!). Though it was not a primary source, it did help me verify the connection between Kirkhoff and Williams that I've been searching. What was the source of your info, and do you know if it is available anywhere? Again, a thousand thanks for helping me on this...it was one of the best breakthroughs this year for me. Scott _________________________________________________________________ MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*. http://join.msn.com/?page=features/virus