all lights on the dash has gone out, engine turns over but will not start, ?

For a while If i turn the side lights on the main head lights flash on and off,turn main lights and they seem to be ok, i was on my drive with just the engine runing and boot open, the head lights came on and alos the wippers, turning the switchers made no diffrence, so turned the engine off all ok went in doors for 10 mins, then i come back out unlocked the car, put key in , turned key, cd came on but no lights on the dash, turned key again, engine turns over but the car will not start ??