I'd like to use AP for the first time, but would like to retain my H1-status (7th year ext). I do not have a valid stamp (infact my passport has an expired H4 (1999), and later I got H1-B(1999) and has now applied for 7th year ext), would it cause any problems in using AP? In other words to use AP do you need to have a valid stamp in the passport?