elseif ($action == 'logout')
{
if (!isset($back_act) && isset($GLOBALS['_SERVER']['HTTP_REFERER']))
{
$back_act = strpos($GLOBALS['_SERVER']['HTTP_REFERER'], 'user.php') ? './index.php' : $GLOBALS['_SERVER']['HTTP_REFERER'];
} $user->logout();
$ucdata = empty($user->ucdata)? "" : $user->ucdata;
show_message('退出' . $ucdata, array('返回上一页', $_LANG['back_home_lnk']), array($back_act, 'index.php'), 'info');
}
$back_act 是标明退出时所在页面的。