hi ann
start by physically unplugging everything that is in the sockets.
try turning the switch on at the mains board.
if the switch wont hold in then you should contact an electrician.
if it does hold in, go along and plug the items that you have unplugged by in one at a time until the switch goes pop again. unplug that appliance as it has a fault.
british jobs for british workers, February 2010