note 53871 added to function.isset

I have a strange problem: function test($b){ if(isset($$b)) { echo "hello"; } } $a = "_SERVER"; test($a); if(isset($$a)) { echo "it works"; } Hello never work as it is in a function. But when the test is done outside the fonction it works ---- Manual Page -- http://www.php.net/manual/en/function.isset.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+53871 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+53871&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+53871&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+53871&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+53871&report=yes&reason=useless Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+53871&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+53871&report=yes Search -- http://master.php.net/manage/user-notes.php