What do you want to do and where do you want to go? Are you in Malaysia right now and do you want to book a domestic flight? For example, from the airport closest to your hotel to cities (Kuala Lumpur, Johor Baru, Khota Baru, Kuala Terengganu, Langkawi), or island (Pinang)?
Click on "Domestic flights".
Do you want to travel from Malaysia to elsewhere (e.g. Singapore, Indonesia, Vietnam, Brunei Darussalam, Thailand), click on "International flights".