Thank you. I must read correspondence more closely! My excuse is that for the past 5 days I've been offline most of the time, as after an abortive attempt to instal a ZyXEL modem, Internet Explorer hangs every time I attempt to use it. That was after, of course, the failure of the BT router but before the power pack packed up . .. This is being tapped out haltingly on a borrowed laptop. There doesn't seem to be an appropriate smiley.