Given the task definition and input, reply with output. In this task, you are given a conversation between a flight agent and the customer. You are given 4 options and you need to select the goal of the conversation. It is provided as part of customer's context, which has to be one of the following: `book`: Make a new reservation, `cancel`: Cancel an existing reservation, `no_flight`: No flight found for the customer's preference, `no_reservation`: No reservation / No change / No cancellation was made in the conversation, mostly enquiring details

customer: Hello. 
 agent: Hello. How can I help you? 
 customer: Next week there was a wedding reception, of my friend to be held in New York. But unfortunately it got cancelled. So, please cancel my flight ticket? I am Susan Allen. 
 agent: Let me check your reservation details, Susan Allen. 
 customer: Ok. 
 agent: There is no reservation found under your name. 
 customer: Thank you. 
 agent: Thank you for choosing us.
no_reservation