I would guess that either the bulb in the dash has blown or there's something wrong with the switch below the handbrake lever. Try replacing the bulb first, all you need to do is remove the 2 screws on either side of the dash and lift it out, then replace the handbrake light bulb, they just screw out from the back. If that doesn't work, remove the handbrake gaitor and have a look at the switch to see if you can spot a problem there and if necessary replace it.