Music Fest Ltd runs a series of outdoor concerts in public parks in Greater London. Following a successful event, the lawn surrounding the Victoria Park bandstand is covered in litter/rubbish.Jane, the director of Music Fest asks Tony, the organiser of the local 'Keep it Clean' association, if his followers can tidy up the litter.He replies, 'We'd be happy to help: keeping the park clean is a public duty and we should all pitch in.'Keep it Clean clear up all the litter/rubbish and Jane is so pleased that she promises the Association a 500 donation.

Is Jane's offer to pay the Association 500 a contractual obligation? Explain the reasons for your decision.