Nels and others, >unfortunately, the site <http://www1.tip.nl/~t596675/sd/sd.html> which >you mentioned doesn't seem to work. You're right, I'm sorry. My site is spread over two URLs, I'm soon putting it all together, but I've to change ISPs first. The next address is correct <http://huizen.dds.nl/~shealiak/sd/sd.html> Timothy