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, I am Jerry Robinson. 
 agent: Hello Jerry. How can I assist you? 
 customer: I would like to cancel my recent reservation due to postpone of my conference at Denver. Could you please help me with the cancellation? 
 agent: Sure, please give me a minute. 
 customer: Sur. 
 agent: Jerry, there is no reservation available on your name. 
 customer: That's fine, thank you for the information. 
 agent: You are welcome.
no_reservation