The first thing I would do, is to create a DB class that manages all the querys and all that.

After you got your DB class, you would begin creating a config file, where you start all your classes, so you create for example $db = new yourdbclass('params');

Then you create a index.php, include your config, and run it. If it displays blank, then you're good to go.

Start creating your user class. There's alot of ways to do a user class, but I would generally do functions in the order they're used:
function to
- check if username and password is correct
- login the user
- logout the user
- register a user
- etc

There's no real "guidelines" on how to do this. But just take it easy and whenever you hit a problem, systematicly errorcheck your script on what could be wrong.

Good luck!

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