facebook authentication using php sdk v4

Yii 1.1 General Discussion
1

I am developing an web application in which I want to log in through Facebook to my application . I downloaded php sdk v4 .please help me.

2

there are tons of ext available

http://www.yiiframework.com/extension/facebook-opengraph/

http://www.yiiframework.com/extension/chybridauth/

http://www.yiiframework.com/extension/yiiauth/