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 Nancy Roberts. 
 agent: Hello, how can I help you? 
 customer: I need a direct flight to attend my Sister's Baby Shower Function in New York. Can you book a flight ticket? 
 agent: Sure, we are here to help you. 
 customer: Thank you. 
 agent: Let me know when you are willing to travel? 
 customer: I wish to start my journey on 10/06 and end on 10/08. 
 agent: Can you share me your source point and destination point? 
 customer: Sure, my origin is from New York, NY - EWR and I want to reach to NY - LGA. 
 agent: Do you need any halts in between your journey? 
 customer: I already mentioned above. 
 agent: Ok, wait for some time. 
 customer: Sure. 
 agent: Thanks for waiting there is no flights found on your details. 
 customer: Thanks. 
 agent: Thanks for approaching us.

no_flight