What do you mean by "manage session"? Sessions are cleared when a page is requested - a script scans all the sessions and removes the ones that timed out. If you close the browser, the session on the server will not get destroyed immediately. Only the client side stored in cookies will. Next time the user visits the site, the old session will be invalidated because of a lack of cookies and a new one will be created. At least those are my assumptions in a general case, not vB specific.