Thank you,

If we same username from different systems it doesn't effect session from used for same user in another system, ASP.net uses seperate session for each request from different systems or different browsers. If you dont want two users to use same username you can make use of database to check if the user is already logged in or not, Or you can use array of users in global.asax file where the data is global for all usersm, so that you control the user while loggin in (Checking with the global array)...

Crap Thank you