There is not specifically any session management in Flex as it runs everything on the client side if at all you want to mainatain you can maintain it on the server side. ...and I think for your case I dont think you need any session managemenet as at the time of login only you can identify which user has logged in to the syetem and based on the user logged in you can load all the previleges of that particular user in the Flex application.
Check out the links below for your understanding...
Thanx for ur answer. But I want multiple users to access the system simultaneously . In that case I will need to maintain session so that I can decide which user to allow what operations. How can I do that in flex?
I think you can do something like as soon a the user log in to the sytem you can return a class object from your server side which has all the previleges
assigned to that particular user and based on that you can allow permissions to allow access to particular sections of your system based on the priveleges.
Hope you got my point.