It'll cost more than it's worth. If it's broken because of an impact with the screen, you're SOL. Neither the warranty nor applecare covers negligence (accidental damage). If it just stopped working, it may be covered under warranty (1 year) or applecare (3 years after purchase if you bought it).
Assuming it's not covered, you can probably find a new panel on ebay for a reasonable price. I replaced my ibook's LCD for about a hundred bucks a couple yeard ago. Even ended up with a whole new lid for spare parts (antenna, microphone, hinges, cables, etc.).