Prevent Multiple login in ASP.NET

Hi All,
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I have to prevent multiple logins for the same user accessing at same time.
i.e. if xyz user is active, no other login should be allowed for the same
user ID.
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I thought of saving active falg in databse. but when user closes browser or
anyhow regular logoff procedure is not called then that user will always be
in active state. So next time he will not be allowed to login.
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Even Session_end() event will not occur if user will close the borwser.
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Please help me if anyone has come accross the same problem.
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Thanks
Bhavini

Even Session_end() event will not occur if user will close the borwser.

Use the application cache with a sliding expiry of 5 minutes. At least this
way your user will be locked out for a maximum of 5 minutes. Additionally
I'd allow a duplicate login if it came from the same IP address.
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Thx for the reply.
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But actually we are having webfarm scenario, so I dont think it will be
possible to use caching here. And another thing is, we cant bear the delay
of
5 minutes. We should be able to login immediately once browser is closed.
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Two scenarios I have in my mind
1) if we can catch browser close event and call logout process there. But
I
am not sure how to catch browser close event.
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2) In DB we can maintain Active/Inactive flag as well as SessionID for
partucular user. So when the same user is logging we can check that
particualr session is activ or not based on session ID. I guess session ID
should be unique.
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"Peter Morris [Droopy eyes software]" wrote:
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