Restrict user login to web and wap at the same time.

I have a web-based system and a wap-based system. Both of the system using same login account from database. So for now, I'd like to restrict the user to login on both site, that means, user only can access wap or web at a time but not same time.

And, I have to ensure same login account unable to login on two mobile phone at the same time.

Any idea on it? How to make it? Or any resources related to it.
Thanks in advanced!

Added a "loggedIn" flag to your DB. Then check and see if they are logged in already. If they are then boot them.

Since some people don't click logout you may need to setup a cron tab to log everyone out with no activity within the last 20 min.

or store the time they last logged in and the device / user agent + ip etc and only allow them to access the pages if the last logged in time is less than x minutes ago and they are on the same device.

if the last login time is older than x minutes just update the table to show the agent, ip etc they are on this time.

pretty similar to vrspectre's suggestion but without the need for cron to execute something all the time.