Possible Duplicate:
ASP.NET authentication login and logout with browser back button
I want to implement logout functionality that will say remove history of only same website
and will not go to the same page when click “back” button from browser after logout.
I want to implement this in C#.
You are going about it the wrong way. You should do a check for “logged-inn-ness” on every page-load. Using your Session-object for example. And if the check fails, redirect to the “LogIn” page.