Java EE (Java Enterprise Edition) General Discussion

Hi
I'm using spring MVC framework to design an application. I'm accepting the user login id and password,verifying it with thw database and then granting access to the next page. The prob is, after logging in if the user clicks on the browser back button and then again next button he is able to do so without asking for his userid and password. How do I prevent this free to and fro movement from the login page to the next page and vice-versa.
Any help is greatly appreciated.