Android : If an object is initialized in the service, do it is kept initialized when service is running in background

I am creating a Login Logout android application, in this application I am interacting with server and when I login the DefaultHttpClient object is initialized and with the login of the user, the DefaultHttpClient is associated with that user and session is running on the server until the app is running in front its initialized. But as soon as I destroy the app, the new DefaultHttpClient object is initialized and therefore it is not associated with previous login but the session on the server is still running because I have not logged out yet. Please Help how to keep my login session running even if the app is destroyed.