Here's a short list of things you need to know before you get started doing whatever it is they do on these things. The script will automatically remove old messages and old visitors. Each user can choose how many messages he wants to see as he talks. The reload button will put any text in the message entry field back there after reloading.
Newest chat is at the top of the page.
The leave button will remove your name from the visitors list and post a message saying you left. Sorry no html tags allowed. See the Non Geek type person that made this script.