Mary brought her diamond engagement ring to Paul Jewelers to be cleaned. She thought she signed a receipt from Paul but he tricked her and she actually signed a negotiable promissory note for $5,000. Paul negotiated the note to Harry, a holder in due course. When Harry presented the note to Mary, she refused to pay. what does the law say? What law is applicable here. What are the "requirements" for a legal/valid promissory note? Were they satisfied here? If not why not