document referer and referrer

http request referer:
Referer http://www.google.cn/search?hl=zh-CN&q=%E6%B5%B7%E8%AF%8D&btnG=Google+%E6%90%9C%E7%B4%A2&meta=

php $_SERVER['http_referer']:
http://www.google.cn/search?hl=zh-CN&q=%E6%B5%B7%E8%AF%8D&btnG=Google+%E6%90%9C%E7%B4%A2&meta=

javascript referer:
document.referrer