Last night driving home I used hi beam then tonight turned on n no hi beam lights didt even flicker just stayed on low beam any ideas?

If you have standard wiring.. then somehow both highbeam filaments have blown at the same time. Or you didn't notice one was already blown.

It is time for 2 new 'dual filament' headlights.

You can check the headlights with a ohmmeter continuity checker.

Chris is right, the most common reason is that the (last) high beam blew.

Another cause could be the switch in the steering wheel has let go. That's not very common however. Datsun 1200 does not use a headlight relay which would be suspect in other Datsuns.

hey i got bored at work so i went out to check them out turns out now they work.. i didt totch any thing lol. some one has put 2 relays in there both clicking. cant find a problem till there is one i gess