title: Clear session on browser close-Native session
body: <p>I am using native session library in my codeigniter  project.I want to destroy the session when browser close.is there any method for that?
  In default session library <code>sess_expire_on_close</code> is there ,But in native session that setting is not there.I notice that native session is using <strong><code>PHPSESSID</code></strong> for the session.is any way to delete <strong><code>PHPSESSID</code></strong> from browser,when browser close?</p>