That's a Sambac 'Maid of Orleans'. I grow a lot of them and I find them to be very easy. They flower on and off all through the year for me- but of course, in winter not as much as when it's warmer.

Give it as much sun as you can, they also get quite thirsty in the summers.

Oooh, you're in Malaysia- not sure what your climate is like, but if it's similar to India, then they should do well for you.