I was currious if there is anyway to check if a user has left the site and if so to send variables they acquired to a txt file on my server.

I'm currently just checking for action every 30 secs and then updating the users variables to the txt file.

This is all just in the testing phase. My theory behind my (madness)method was that I would not be slowing down the site a terrible amount by sending variables every 30 seconds opposed to instantly sending them upon being created. And if the user does leave I only lose what variables they created in the last 30 sceonds.

Any insight from you veterans would be very much appreciated!!

Thanks
Chris