Worried about the call time
And going over the time allowed then use a mobile phone which most people have
And set up an alarm call on the mobile, that way you cannot go over the call limit.
Or buy a timer you can see from this example to give you some idea click
http://www.maplin.co.uk/module.aspx?TabID=1&criteria=usb&ModuleNo=26574&doy=search&C=SO&U=Strat15Regards Barry
