Php Log in script

is it possible that after a user have logged in on m开发者_开发技巧y site, then he pressed the back button, it will not go to the previous page or the login page again else it will be replace by another page?

As soon as user is logged in, create a new session.

When the login page is loaded, check the session for login information. If user is logged in, redirect to desired page. Otherwise, don't do anything, just display login page.

On the code to load the login page, you can detect if the user is logged in, and if so, redirect to the desired page. How this redirect is done will depend on what framework you're using, if any.