Proxy Pac - Javascript problem

Hi all,

I manage a very complex infrastructure with about 4 proxy pacs deployed via GPO. Now i need to split internet/proxy access based in user location. The problem is that our LAN is not properly segmented (a lot of subnet mixing around the country) to proxy pac files analyze user location based on user network. I have to figure it out a solution based in javascript function like:

Proxy Pac files (some kind of possibilities):

- javascript function to detect dhcp server that computer has (this will give me user location and then i can redirect to specific proxy)

- ...

anyone knows if this is possible? any suggestions?

Kind regards,

LC

Luís Carmo