如何在不注销的情况下让用户无法返回注册/登录页面？

Question

I am creating a website and the index page is a login/signup page, and i need it to be impossible for the user to go back to that page unless they log out. How would I do that?

Answer 1

Put something like this at the top of the login/signup page:

if($_SESSION['loggedin']) {
     header('Location: loggedinpage.php');
     die();
}