well the low beams are held in with a clip in the headlight, if someone had removed and replaced the bulb they might of damaged the clip which wont hold the light or the clip might be unclipped, cause the low beam bulbs are pretty hard to figure out how they work untill you finally take it off and look at it...
I would check that 1st first
If you cant figure out the low beam headlight clip cause its pretty hard to figure it out for the 1st time....
