How to restrict multiple login using a single account

[shankhar]

Hi all,

In my project there is a requirement. If a user logged in at a time since he/she logged out others are not allowed to loggin using the same user name. That is to avoid multiple logins using a account. How to do this?

I had got a idea and implemented.

1. When a user logs in storing the username, ip, login time to db.
2. When a User logs in i'll check the table whether the username exists in the table or not if yes i'll not allow the user to login else i'll allow to loggin.
3. When he logs out i'll delete the record from the table. Then he/she can login again.

But there is a problem in this the user can close the browser directly or right click in the taskbar and close it or by pressing Alt + F4. So for this i have to catch the things in Javascript and trigger the logout.

Is is possible to catch the events in Javascript, if yes please provide me.

Or Is there any other method to restrict multiple login using single account.

Thanx in advance.

[The-Master]

Why not just delete the record from the table after a certain time of inactivity, say 15 minutes like myspace does with its "online now" thing where it just stays there until you haven't gone to a new myspace page for 15 or so minutes. This would stop the problem of people not being able to log in if their browser crashed or they didn't have javascript turned on.

[NogDog]

If you are a using a session-based login method, you could set the user's IP address as a session variable when s/he logs in, and then only allow access if the current request's IP matches that in the applicable $_SESSION element.