Could try airline websites or calling a travel agent. Some of the online travel agents have minimum time to ticketing that would preclude their use.
Your best bets within the next 24 hrs are probably:
- Qantas/Jetstar via Perth,
- Qantas to Singapore and then Jetstar/Singapore/Air Asia to Jakarta
- Singapore Airlines via Singapore
- QF/DJ to MEL, PER or BNE then midnight Singapore Airlines flights to Singapore (Or Malaysian to KL) and on to Jakarta
- Malaysia Airline via KL
- Garuda via Melbourne/Bali