All in one guestbook-shoutbox-chatroom

This little project came to be when I couldn't find a shoutbox that was quite to my liking. I'm no expert with PHP, and the coding is far from elegant, but it seems to work well enough as a shoutbox/guestbook/chat script. I know it could be improved upon. After a couple of people asked if they could borrow the script, I kinda packaged it up as you see it now (mainly, I just moved some user variables to an include file for portability) Features: -Functions as a guestbook/shoutbox, but also as a quasi-chat room by virtue of a silent refresh - no annoyong IE 'tick' - (it really isn't very efficient as a chat room, but I've used it that way on my webcam site) -Displays the national flag of the visitor (courtesy of an IP lookup at www.hostip.info) -Tooltip display of IP, date, time of post on mouse over a comment (to reduce clutter) -Site owners comments receive a distinguishing highlight, and the site owners name cannot be used by others - see comments.inc.php for explanation