looking for someone to have voice chat with

Hi, I wanted to create a voice chat which will work in a lan. Would you help in that. I know that it needs sound api, jmf. But I want to know the steps for creating it. Like how do I transfer voice on the client side(other computer) so that the person on that computer will hear it through...

My computer audio mixer could not be initalized . Let me know how to rectify.

I have a network between four laptops by wireless, but they don't have internet access.. I want a software or something so that we can talk to each other through headsets.... Could you please help me how to do that? Thanks