hi,
im writing this program for the internet lab of our dorm where everyone can access the net for 45min, and a server can control all times(add, decrease,send msg to user and so on) , I wrote a program using using TCPCLIENT and TCPSERVER classes, the timer is on the client, and sends its time to the server every minute,and the server can send messages to the client ( set time for timer and ,,,) the problem is if the client computer shuts down or is unexpepticly rebooted, how can the server know about it ??? is there anyway to this ?

thanks,