<?php
if (isset($_SERVER['PHP_AUTH_USER']) &&
    isset($_SERVER['PHP_AUTH_PW']))
{
    echo "Welcome User: " . htmlspecialchars($_SERVER['PHP_AUTH_USER']) .
    " Password: " . htmlspecialchars($_SERVER['PHP_AUTH_PW']);
}
else
{
    header('WWW-Authenticate: Basic realm="Restricted Area"');
    header('HTTP/1.1 401 Unauthorized');
    die("Please enter your username and password");
}
?>