Usernames and passwords are stored in an array in the check-login web page.
Action page of login.php:
login_action.php
<?php
// Array of users: username => password
$users["admin"] = "adminadmin";
$users["vadim"] = "vadimvadim";
foreach($users as $name => $password) {
if($name == $_POST["username"] && $password == $_POST["password"]) {
// Username and password are correct
header("Location: private.php");
die();
}
}
// Username and password are incorrect
header("Location: login.php")
?>