<?php
include 'databaseinfo.php';
/*This is the information to use to connect to the MYSql database */
$dbhost = '$dbhost';
$dbuser = '$dbuser';
$dbpass = '$dbpass';
$dbname = '$dbname';
/*If the connection could not be made show this message*/

?>

<!--Registration page!-->
<form>
  <input id=name>
  <input id=password>
</form> <!--After submit, link to input-user-page!-->

//input-user-page
$name = $_POST['name']
$pass = $_POST['password']

query_insertuser($name, $pass) //make some mysql code from this

<form>
  <input id=name>
  <input id=password>
</form> <!--After submit, link to user-validation-page!-->

//User-validation-page
$name = $_POST['name']
$pass = $_POST['pass']

$result = query_validation($name, md5( $pass )) //compare name and password with those in the database (this is all psuedo code!!)
if (result == true) { //user validated! (of course, this is pseudo code too)
  $_SESSION['userId'] = $name //We'll keep track of this user now
}

else {
  header("Location: index.php") //no validation, be gone!
}

//function to be called in every page that requires login
if (!empty($_SESSION['userId')) { //user exists
  echo("Let's drink a beer mate!");
}
else {
  header("Location: index.php") //not validated, be gone!
}