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: Hi, Richard White here. 
 agent: Hello, how may I assist you? 
 customer: I want to cancel my reservation due to my sudden health problem. Please help. 
 agent: White, no reservation found with your name. 
 customer: No problem. Thanks for your information. 
 agent: Thank you, have a nice day.
no_reservation