Basically, the meaning of the two expressions is the same. You put them at the beginning of conversation to know how your friend is doing. If I had to point out the difference I'd say that "jak się masz" concentrate more on the person you are talking to, whilst "jak leci", is a more general question. This is because in the question "jak się masz" there is implicit "ty" - "jak (ty) się masz". So, to summarize: - jak się masz? = how're you doing? You ask directly- "ty/you". - jak leci? = how's it going? You ask about things, generally.

ni kmarin saya ru dapet polis asu ransi hehehehehe , .......... just kidding ..... if u free , u can come to my boarding house or we can meet in the tebet ..hehehe

jak się masz: how are you? jak leci? :how you feel (how is flying...)