proto-man

sorry to bother you again but what would be the code for internet service provider. Thanks for your help on my previuos question.

I am just wondering if $HTTP_USER_AGENT is used to find the viewer's browser or the user's os. In some pieces of code in this thread, i have seen people using it for os and browser? Very Confusing to me. Please help me out. Also, what would be the code to find the users isp. Like i know the ip code is $REMOTE_ADDR.