Dear(thenameofyourboss),
Iregrettoinformyouthatidecidedtoresignfrommypresentpositionas(position)witheffectivefrom(nextdayoflastdate).
thankyouforgivingmeachancetolearnandtogainthevaluableexperiencein(companynameandsectionworkwith).ihopemyresignationwouldnotcauseyoumuchinconvenience.
thankyouforyourkindattentionandwouldappreciateifyoucouldletmehaveareferenceletterbeforeileave.
yoursfaithfully,
(yourfullname)