Allow internet for WAN user in ISA 2006

I installed isa 2006 in my work group environment.I have more than 10 branch office and each are connected by LL. I configured isa server to access the internal user to access internet.at present i am adding ip address(those who want internet) in internal network. Is any other way to add network and allow that network to access internet so that i can allow different policy for different branch office user. I added network set and created policy to that network to access internet.but its not taking that network.only ip’s included in internal network is getting internet.

I appreciate your help in this regard

Thanks and regards
rujinraj