//session ¼òµ¥²Ù×÷

//sessionÌí¼Ó

@session_start();

session_register("userSession");
$_SESSION["userSession"]['id']=$id;//Óû§id
$_SESSION["userSession"]['nick']=$nick;//Óû§êdzÆ
$_SESSION["userSession"]['group']=$group;//Óû§×é

//sessionɾ³ý

@session_start();
if(isset($userSession))
  unset($userSession);
session_destroy();