Iam giriş sistemi olarak benim php projede lightopenid kullanarak ve kullanıcı kimlik doğrulaması iptal ve geri siteme döndükten sonra, ben o kimlik iptal etti hangi site den bilmek istiyorum.

For this, i tried the php HTTP_REFERER, but it is not able to get me the real site url. Suppose the user came from yahoo authentication page, i want to know that it is yahoo url.

How can i achieve this? Basically i want to know how to get the previous page url in php, if that works.