no+light+on+charger

Check to see that your charger is seated correctly - unplug the charger, and replug it in. (This happens to me often.)

If the charger still doesn't have a light, make sure that the power strip is turned on or the wall outlet you plugged into is working.

As a last resort, ask a friend to borrow her charger and see if that charger will charge your computer.

If your computer doesn't charge with your friend's charger, or if the charger doesn't work....time to....

If everything is good...