in most cases you will need to replace the screen.
sometimes it might be possible to replace the backlight lamps, but you probably won't be able to buy lamps on their own. you will need to open the lcd cover and check whether you can remove the lamps.
if the lamps are replaceable, you can search ebay either for laptops with smashed screen (and hope that the lamps are ok-they usually are) or just search for the replacement screen...
good luck,
raf
dupalopez, June 2007