Shaoib found it well,
Whenever such an issue occur, check 2 things that could be problematic.
1) Battery + it's terminals: Sometimes the rusty terminals dont spark, also the battery might itself might have been a problem. There is a small connector under the ignition point, sometimes it gets lose. Try to kickstart battery by connecting another charged battery with it, (if the battery cables are not available, simply try to join other battery's terminals with yours upside down). Another way to test your battery is to place a steel key alongside motor belt (at bottom left side, under air filter) if the battery is good, it will attract the key towards itself due to magnetic field due to charge
2) Plugs: A heavy wash could result draining the plugs, get them out, dry well, replace.
My problem was solved with a replacement of batteries as they were all dead. i got 50 Volt batteries instead of 40 with replacement of older one, in PKR 2900.