on elements of second dual of a hypergroup algebra

Let h be a locally compact hypergroup with left invarianthaar measure and let lp(h), 1  p < 1, be the complex lebesguespace associated with it. let l1(h) be the set of all locally measurablefunctions that are bounded except on a locally null set, modulo functionsthat are zero locally a.e. let  2 m(h). we want to nd out whenf 2 l1(h) implies that f 2 l1(h). some necessary and sucientconditions is found for a measure  for which if f 2 l1(h) for everyf 2 l1(h), then f 2 l1(h).