you can write '알리사' or '앨리사' both are fine. but you are from phillippines that you mostly have american accent. so I would go for 앨리사 cuz it sounds more like '앨리사', but if you are from UK or AU, NZ, I can recommend '알리사' cuz it sounds more like their pronounciation. so it's all about you, not all about us when it comes with names. :) hope it could be helpful for you.