MacBook air not charging

My MacBook air is nearly 2 years old and has worked fine (apart from wireless issues) and now all of a sudden it just won't charge. It was fine the day before but today nothing - no light on MagSafe charger. I have tried my hubby's MacBook charger but that doesn't work so it isn't the charger. I have tried an alternate socket so not that and I have cleaned the magsafe port and leads. Any other ideas? I need it for my final assignments