Well it could be the element, which heats up and then has air blown over it, which is then sucked/pushed into the dryer, or it could be the belt, which runs the fan has fallen off or snapped.
Look at the rear of your machine, at the bottom is a cover with a single screw holding it in place. Remove the screw and the cover and see if the belt is attached.
It should go around the red pulley on the end of the drive shaft - for a picture of the pulley see:
http://www.flickr.com/photos/ragebe/4520772357/in/set-72157623730027559/
and the other end goes around the fan pulley.
If the belt has broken, then you can buy one from here:
http://www.espares.co.uk/parts?k=tc470+belt
and if it's the heating element burnt out, then you can get one of those here:
http://www.espares.co.uk/parts?k=tc470+heating+element
which is somewhat more expensive.
Ragebe
April 2010