I have a form with 6 buttons, as well as one "CONTINUE" button. Users are required to check at least one of the 6 buttons and then press "CONTINUE" to proceed. Because some of the users may not be very familiar with computer, some may simply check the buttons and sit there. In order to avoid such a situation, I would like to keep track of when they press a button last. If they have no action for, say 15 second, I would like to prompt them to press "CONTINUE". However, if they check another button, the process begins all over again, i.e., a message will be prompted if no other action is taken for another 15 second. Does anyone know how I can do that? Thanks in advance.

Chu