Glamorous Grannies

Tom has a bet with Diana that she can't be nice to people for a week. Such untypical actions only lead to confusion.
Baines wants to organize a glamorous grandmother contest for the old ladies in the home, the prize being a cruise for two.
Since Basil wants to marry Betty, Tom approaches his son-in-law Geoffrey, whose firm are sponsoring the contest to let Betty win, but when Betty gets cold feet and refuses to enter, Diana, having made sure a journalist friend is present to expose any 'fixing' the contest; replaces her and wins. She lets Betty and Basil have the prize.