Q: 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. 
 agent: Hello, how may I best serve you now? 
 customer: I want to change my reservation. Can you help me for that one? 
 agent: Sure, I can change your reservation right now. Before that I need to know your good name please to track the details? 
 customer: Sure, Justin Nelson here. 
 agent: Ok, Please stay online, I will check the previous list and revert to you. 
 customer: Sure. 
 agent: Thanks for remaining so positive. We are sorry to specify that, there is no active reservation found on your name. 
 customer: No issues, thank you for your time. 
 agent: Thanks for choosing us, wish you a great day.
A:
no_reservation