http auth .. again

once i run this code, and grab te username and pass, how can i exprire this auth? i tried using Header("HTTP/1.0 401 Unauthorized"); and that gives me another window, but the next page i go to still gives me access, i also tried $PHP_AUTH_USER = ""; $PHP_AUTH_PW = ""; and that doesnt work either, any ideas? Can someone explain how realm works?? If i changed the realm, should it ask me for a password again to? HELP! if(!isset($PHP_AUTH_USER)) { Header("WWW-Authenticate: Basic realm=\"1\""); Header("HTTP/1.0 401 Unauthorized"); echo "Text to send if user hits Cancel button\n"; exit; } else { echo "Hello $PHP_AUTH_USER.<P>"; echo "You entered $PHP_AUTH_PW as your password.<P>"; exit; }