Screen size, browser on php

Hi I have a small problem. I'm working on a traffic and banner xchange application, and my client asked me to retrieve as info, for each banner that is displayed or for each traffic entry the user's screen size, operating system, browser type and original language. I've found this stuff into a javascript, but I need to be able to retrieve it through php, only in one file. The javascript is doing this through 2 file, one get the info, and passes it to a form in the other. So, my dilemma is if Is there a way of getting from php the screen size? (The rest are revealed through the server variable user agent($HTTP_SERVER_VARS['HTTP_USER_AGENT']) & language-($HTTP_SERVER_VARS['HTTP_ACCEPT_LANGUAGE'])) Or, do you have knowledge of some script like that that's on the web ? Thank you for your help. Petre Nicoara