Second (Bizarre) Question regarding PHP and ASP

I don't know how to post this one so I'm sorry for such bizarre cross-posting, but honestly I don't know where to go for help on this one! I have process.php that has to call a remote file called process.asp on another site. Site 1 has the cookie domain I want (that's where process.php is housed) Site 2 has the database I need (because I can't obtain a database for Site 1 - Site 2 is where process.asp is housed) process.php has to do an fopen to process.asp to process username and password material. process.asp needs security, obviously, to ensure that the user is "coming" from process.asp (but he's not because he's doing an fopen). in other words, process.php opens up process.asp and returns the evaluation of process.asp onto process.php I tried using REQUEST_URI but I didn't get the results I wanted. How will process.asp know that process.php called it in order to do what it should do? Thanx Phil