How to use vBulletin user database with external PHP scripts?

[Inocybe]

I would like to use the vBulletin user database with my external PHP scripts. How would I do this?

This is just an example:

<?php
include "vBulletin user file(s).php";

if($_SESSION['user_level'] > 0){
echo "Welcome ". $_SESSION['username'] . " , you have logged in";
}
else
{
echo "Please log in (link to vBulletin login page)";
}
?>