I just installed WPMU DEV Chat plugin. I get a pop up box when I am logged in as Admin on my site. However, I can't get it to open as a chat box when logged on as other users. I also don't see any type of address for choosing which other users I want to chat with. I want it to be available to other users, but to be private and only for logged on users of the site. I looked at Settings but couldn't figure it out.