It won't close or won't lock? if it won't close see other replies - if it won't lock can you hear it working when you push botton?
If not possiblly loose/broken wire (normally where wires come through from roof) = quite tricky to fix - if so maybe small rod dropped off?
Colin, April 2012
latch may be in closed position, so you will have to unlock vehicle and while keeping boot button/handle pressed flick open latch with a screwdriver or similar to release it
k, April 2012
has boot latch bolts came loose and its moved to far away to latch