Dryer Stopped Heating Up

I have a maytag dryer I have owned for nearly 20 years the thing has stopped makeing heat. The motor runs and the fan blows but no heat. I have taken it appart and the heater assembly appears to be fine there are no breaks in the heating element. The fuse tests as Ok with an Ohm meter and thermal switch shows no readings at all with an Ohm meter. Does any one have any ideas as to what might be wrong? Thanks G