Post a question on www.ukwhitegoods.co.uk if you want a decent definitve answer but......when you say its gone off , what do you mean ? That its not heating ?

I'd never condone live testing on an appliance but you could check the dryer heater for continuity . From experience , it should read between 25 - 45 ohms . There may be an overheat stat too which might have popped which will cut the circuit to the heater but then something must have caused this to pop.

Check out the forum on the above site and you may find more info on there

POWER OFF AND PLUG OUT IF INVESTIGATING