Allowing access to a page from a certain referrer

Hi,

I have a page on my website and I want it to be accessible only by people who visit it from a certain referring site.

Let’s say my page is this:

http://www.mysite.com/my-page.php

And the referring site is this:

http://www.allowedsite.com/

I want my page to be accessible only by visitors coming from the allowed site. Is there a way to do this with PHP?

Thanks.

The first thing I would do is put a dummy page up with the following

<?php var_dump($_SERVER); ?>

Then navigate to that page from allowedsite.com

You will see the variables that were developed with this request on the page (better formatted if you do a view source)

I believe there is a HTTP_REFERER_URL variable inside $_SERVER, but it has been my past experience that the field isn’t always populated.