Controlling Access

I have an application that consists of some 30 php modules. Each one links to another, as you can imagine. How can I create a security mechanism that only allows the modules in my system to be called from one-another? I do nto want any of the modules to be called by typing them on the address bar. Of course, sessions takes care of folks who have not logged into the system, btu I don;t want registered users hacking around either. I though of using HTTP_REFERER as a handshake restrictor, but it seems to be unstable and unreliable. Any suggestions? D ------------------------------------ 'Marketing that Listens" ------------------------------------ Doug Wolfgram CEO - GRAFX Group, Inc. www.gfx.com www.aimprojects.com 949.433.3641