If headlights will not work in 2002 Hyundai sonta what can be the problem?

Are both lights out at the same time. Have you changed the bulbs and if you have they still dont work there is a relay and or fse for them in the fuse box. Check the fuse and see if it blown and check the relay and see if it clicks when you turn the lights on. If it dont click you might also have a bad switch for the lights