warning: page has expired

I'm working with struts. and after login when I click any link and then go back..the page is giving warning page has expired.
What's the problem?
What am I doing wrong?

thank you

check if the previous page you are going to is in session scope or request scope.

Hi, I'm using session scope in previous page. I'm using

Code:

---

session.setHeader("Cache-Control", "no-cache"); response.setHeader("Cache-Control", "no-store"); response.setDateHeader("Expires", 0);
response.setHeader("Pragma", "no-cache");

---

in my jsp page.
I removed this and it worked!!


thanks heather