Create a very simple Chat program using PHP and MySQL

Simple Chat program written in PHP using a MySQL database. I have created this using a local host, rather than an online version,
just so that students can learn how to make it and test it. I will work equally as well with a real ISP and live website.

[Timatej]

how can i keep my chat always on a new message?

[meandmyself]

QUESTION: best tutorial ever if you ask me, everything works, UNTIL you change it from update to insert, then it gives me an error message like "Error: INSERT INTO chat1 (Message) VALUES ('test')
Field 'id' doesn't have a default value" but you shouldn't need the id for the insert, only the update, right? HELP, thanks!