I see you have done the easiest checks first, well done. If the fuses are fine, check the bulbs themselves as each build houses the low and high beam filament. If they are faulty replace them. They usually fail as a result of age, vibration, oil residue contamination from fitting.
They are called mini blade fuses Fat Pete
Try Replacing turn signal flasher
I have 2000 accent, my fuse box is to the left of your feet as you sit in the drivers seat, on the side panel. There should be a small door. Hope this helps you out.
I'd check all the fuses
have you checked your fuses? it could be as simple as that This is true, there is a separate fuse for the high beams, low beams and radio. Fuses for 1999 LHS are located behind a side panel (drivers side) of the dash next to the steering column. Driver's side door must be open and there is a wiring diagram on this panel.
The ignition switch could be bad if a Hyundai Elantra has no crank and then starts. The fuses which are tied to the ignition should also be checked.
There are a few things to check, first are the bulbs good? high and low are separate elements and the low could be blown out. Second is check the fuses, high beam and low beams often have separate fuses. Third would be the dimmer switch.
try new light bulbs
My 1999 Hyundai Accents has the wiper fuses on drivers side ,look for box way down under the knob to open up your hood ,i found this out by blowing my wiper fuse a few days ago after an ice storm
Check your fuses.
The headlights are on two different fuses. The high beams are on one fuse and the low beams are on another fuse. The fuse for the low beams may need to be changed.
Headlight dimmer switch is defective