How to check Activity status of client and act accordingly

Hi,

I need help and suggessions to implement the following in asp:

Whenever there is no activity detected in a client PC (ie, no keystroke or no mouse inputs -- similar to screensaver) for a particular period (which should be customizable), an alert needs to be thrown to the user stating "Are you still working?" with a default timer of say 5 seconds.

If the user responds by clicking YES button, the application should go back to background mode & wait for inactivity again.

If there is no response received within that 5 seconds, it should connect to a Oracle Database & execute a procedure with certain inputs.

How can this be implemented, if all users are expected to be working on Windows Desktops.

Thanks for you help.