Joe, I have been waiting to reply until seeing the code, but the code is still not loading for me.
But at least let me say that it looks like you have created a really interesting demo and I look forward to playing with it. The early parts of the video are so fuzzy as to be illegible, but the later parts show what you have done, very well. Thanks for this contribution. I hope it is as revealing as it looks. -- (B=) ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
