My name is Thitima Chaorai Presently I am working as a asst. sales engineer in sales & marketing department. Due to some personal reasons, I would like to resign effective .....(ใส่วันที่ที่คุณจะให้การลาออกมีผล)
Please treat this letter as my resignation request for your approval process accordingly.
Sincerely Yours,
(Miss Thitima Chaorai)