Browsers on terminal server

I am using $_SERVER["REMOTE_ADDR"] to get address of the browser accessing the system and then using gethostbyaddr() to get the machine name. This worked great until I came to a site using M$ Terminal Server to provide the terminals. We still need to know what machine we are talking to, so we can identify the room, and flag the correct set of displays, but $_SERVER["REMOTE_ADDR"] seems to be giving only the IP address of the TS machine. Anybody been here already. Is it possible to identify the terminal that is browsing on the other side of TS. Any pointers to some help to restore operation in this situation. -- Lester Caine ----------------------------- L.S.Caine Electronic Services