如何在用户会话到期时重定向到页面？

I am currently working on an web application that uses ASP.NET 2.0 framework. I need to redirect to a certain page, say SessionExpired.aspx, when the user session expires. There are lot of pages in the project, so adding code to every page of the site is not really a good solution. I have MasterPages though, which I think might help.I am currently working on an web application th