session_destroy() - what this function really do? additional info

Hello All, One moment ago I discovered strange (IMO) behavior of session_destroy. I wrote something like that: session_start(); session_unregister("user"); session_destroy(); After executing that code I found variable $user being still registered in session.. After some time experimenting with it I get my variable unregistered from session by.. removing session_destroy() from code. Destroying session caused all the time resetting session variables to state from session state. I feel a little bit confused.. Does anybody know (and can explain me) what session_destroy() do??? thanks in advance -- Sebastian Baran, Poland mailto:sebab@info.com.pl