(function() {
    // Get the user from localStorage
    const user = localStorage.getItem('user');

    // Check if the user object exists. If not, redirect to the login page.
    if (!user) {
        // Use window.location.replace() to prevent the user from clicking the "back" button
        // and re-accessing the protected page.
        window.location.replace('/frontend/index.html');
    }
})();