"reffered from" environmental variable?

I'm putting together a shopping cart that will be hit from two different web sites and I would like to track where the order came from by setting a cookie. Is there an environmental variable that I could pull instead of giving each web site a different url to point to the shopping cart? I've tried using the following; if (!isset($parasite)) { $parasite = getenv ("REMOTE_HOST"); setcookie("reffrom",$parasite,time()+86400,"/",".flylikeaneagle.com"); } That seems to set the browsers ip address not the ip address of the server that's hosting one of the two sites that will be using the shopping cart. Any help would be appreciated, Tom >>.>>.>>>.>>>>>.>>>>>>>>>.>>>>>>>> Tom Beidler Orbit Tech Services 805.682.8972 (phone) 805.682.5833 (fax) tom@orbittechservices.com http://www.orbittechservices.com/ >>.>>.>>>.>>>>>.>>>>>>>>>.>>>>>>>>