Help! My lights have died!

[John.P]

Supposed to be driving tonight to see the g/f, but after pulling out onto the road realised my headlights have gone. Typical - working perfectly yesterday night, nowt today. Sidelights ok, light switch seems to be working ok, fuses are fine & relay is clicking when i switch the rotary switch to headlights and when you move between dipped / main beam (blue light comes on on dash). Really dull call for help I know but any ideas where to look next to save me from being in the mire for the rest of the weekend?