Automatically destoy the session when the browser closes

HI,
thank u for giving a reply. but it does not work

In settings.php i chaned three things they are:

ini_set('session.cookie_lifetime', 2000000);

with
ini_set('session.cookie_lifetime', 0);

And

ini_set('session.use_only_cookies', 1);
with
ini_set('session.use_only_cookies', 0);

And

ini_set('session.cache_limiter', 'none');
with
ini_set('session.cache_limiter', 0);

i made all these three things bbut it doesnot works.It works fine only at the time of manuualy clear the cache and cookies in the browser ,but i donot want like that .I want Just by close the browser the session destroyed .
If any one know please help me, regarding these.

thanks in advace.