HI
Let me explain about my problem:
I have a Silver-Light application developed base on Prism. In This app we need to use User/Password (Authenticate Our user`s) for separating permission levels. So for Doing this We wrote method in Service App (WCF web service) for detecting user and if User is valid-one, user can use App. After that(Detecting method) as Result method return valid user.
For using this User-Information we need define Global User-variable, and any Modules can access to this variable. But there is another big problem. We must define User-variable Per Session (any User work with his\her user-variable). Also in any calls from modules the new session will be create.