Stupid questions first: Is the whole laptop connected from the plug socket, to the transformer pack and then to your laptop? Is the plug turned on? Has it worked in the past?
Proper questions second: Do you think you have wiped your hard drive by accident? Have you downloaded a virus without knowing? Have you dropped it at all?
If that doesn't sort anything, then maybe it's the power supply. Possibly take it back to the shop it came from.