yeah sorry but i'm totally lost.  Management is beginning to think it may be more cost efficient to create our own IM? 

I edited the Global.asax:

public string GetUserUniqueName() 

  {
   if(Context.User.Identity.IsAuthenticated)
    return HttpContext.Current.Request.Cookies("username");
  }

... now what?  please outline the steps needed to get this thing to work (with some more examples).  thank you.