How do I make a chatbox that reads a username from MySQL?

Hey all, so I'm just trying to make a basic chatbox on my site that users will enter in a message and it will display in the box.

To get to the chatbox, users will already be logged into the site. So in the chatbox they wouldnt have to enter开发者_运维百科 in their 'Name'. Just a message.

What would be the best way of doing this?

You wouldn't read the username from the database. If a user is already logged in, then you should have (or should use) a username in $_SESSION["user"] for example.

Your chatbox could use nothing more than a simple text <input> that you then receive server-side and store it into the database:

db("INSERT INTO chatbox (user, message, time) VALUES (?,?,?)")
-execute( array($_SESSION["user"], $_POST["input"], time()) );

Which then again is pretty easy to read out and display as a chatbox. (Maybe add a bit of AJAX polling once you have that working.)