How to disallow to access my website if someone have cookie from exam.com website? [duplicate]

This question already has an answer here: Closed 12 years ago.

Possible Duplicate:

How to check cookie from other website in php and do not allow to access mywebsite?

How to disallow to access my website if someone have cookie from exam.com website?

i tried fo开发者_如何学Cr about this in php . please help me thank

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The answer is simple : you can't because you can't read cookies from other domains.

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You can look at the referring URL though. To see if they came directly from exam.com. $_SERVER['HTTP_REFERER']