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 Samuel Phillips. 
 agent: Hello, how can I guide you for today? 
 customer: I would like to visit Orlando, MCO to enjoy the Deep sea fishing with my friends. Can you book me a ticket within the range 200? 
 agent: Sure, can you please share on what dates you are willing to travel? 
 customer: /I want to travel on 11/12, and need to catch return flight on 11/14. 
 agent: May I know your nearest source airport code? 
 customer: Source is from Boston, BOS. 
 agent: Sorry, there is no flight available on your requested dates on this route. 
 customer: Ok, no issues. Thanks for the information. 
 agent: Thank you for contacting us, have a nice day.
no_flight