how to record the referal of the referal?

Hello friends! i'm stuck with something i cannot resolve =( i'm programming an statistic sistem, and for tracking the visitors of a page, the systems works this way , a code in the user's page open a page on my server and a script generates a image using the gd library( showing an ok if everything is right, or a err if somethings goes wrong )... well, everything is right with the system, but how may i record the referrarls of the user's webpage?, i've tried using the HTTP_REFERER, but it comes with the value of the user's page ( with it's perfectly right, cos' i called my script from the users page..but it's not what i want ) how may i get the referal of the referal that comes with the HTTP_REFERER? thanks a lot for your time.. -- Best regards, lexter mailto:lexter@swissinfo.org