# Loads user information, logs users in and out, controls cookies
my $user = My::Authentication->load;

# require a user to be an admin or redirect them to the login page
$user->require('admin');

# require a user to be an admin or redirect them to a specific page
$user->require('admin', '/login.html');

# require a user to be an admin, or give them an "Access denied page"
$user->require('admin', undef);