How to logout from a login page in asp.net -

whenever click on logout button redirect me login page when im clicking on button redirect me last visited page. not using membership or windows authentication.

session.abandon(); response.cache.setcacheability(httpcacheability.private); response.cache.setcacheability(httpcacheability.nocache); response.redirect("loginform.aspx"); 

if using session destroy session value on logout button click , can put check in app webpages

if(session["sessionvaribale"].equals(null)) { response.redirect("logoutpage url"); }