Detailed Instructions: 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
Problem:customer: Hello. My name is Joshua Wright. 
 agent: Hello Joshua. How may I assist you? 
 customer: Suddenly my trip is changed.So I want to cancel my reservation. 
 agent: Sure. Sorry Mr. Wright, I didn't found any reservation with your name. 
 customer: Ok, thanks for your help. 
 agent: You are most welcome.
Solution:
no_reservation