Basic HTTP Authentication Prompt in PHP

Prompt users with a basic HTTP authentication dialog.

Source Code

if (!isset($_SERVER['PHP_AUTH_USER'])) {
    header('WWW-Authenticate: Basic realm="My Realm"');
    header('HTTP/1.0 401 Unauthorized');
    echo 'Text to display if user hits Cancel button';
    exit;
} else {
    echo "
Hello {$_SERVER['PHP_AUTH_USER']}.
";
}