I used all the process for destroying session.
header("Cache-Control: no-store, no-cache, must-revalidate, max-age=0");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
session_destroy();
session_unset();
clearstatcache();
But when i click the back button it show my previous page with session value. I don't know how to solve it. please help me.