try looking at the headlight fuse first, if that seems okay then pull the bulb and look at it, chances are the low beam is burned out. First things first-does the bike start and run? Does the headlight work on high beam? Above all when something suddenly comes up on a motorcycle don't panic, take a step back and think what is the simplist things to check first-chances are it is gonna be one of those--either the bulb is bad or the fuse is blown. If neither of those, THEN come back and ask a question or get a manual and start testing the wiring for shorts, or opens