How do I make 1200 dollars fast?

i was invited to London by a friend, in a little over a month. We are going from JFK to Heathrow (London). I need money for my passport ($80), plane ticket(988) and spending money (roughly 100 bucks). I'm 14 years old and turning 15 in a week so I'll have birthday money. But that won't cut it. How do I make the money!! Help!!