Description
bool 
session_unregister ( string name)
     session_unregister() unregisters
     the global variable named name from the
     current session.
    
     This function returns TRUE when the variable is successfully
     unregistered from the session.
    
注: 
      If $_SESSION (or
      $HTTP_SESSION_VARS for PHP 4.0.6 or less) is
      used, use unset() to unregister a session
      variable. Do not unset() $_SESSION
      itself as this will disable the special function of the
      $_SESSION superglobal.
     
| 注意 | 
| 
      This function does not unset the corresponding global variable for
      name, it only prevents the variable from being
      saved as part of the session. You must call unset()
      to remove the corresponding global variable.
      |