Then it could mean either one of two things(possibly one). You need a new AC adapater. Call you laptop manufactorer(if you have a warranty) and request a new one. I know the help support is usually horrible(Indian accents). But just bare with it and you'll get your AC adapter rush shipped to your house. Check here for a pretty comprehensive amount of AC adapters.

The other problem could be that your battery is dead. And if that is the case just call the company from which you bought the laptop from. If you didn't buy it from a company. Lets say a friend, then just buy one from the link proved above. Same applies for the AC adapter.