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 can I assist you at this moment? 
 customer: Can you please help me in changing my existing reservation? 
 agent: Sure, I am here to help you with this. 
 customer: Thank you. 
 agent: Can you please provide your name to check your reservation status? 
 customer: Sure, my name is Carolyn Hill. 
 agent: Wait a moment please. 
 customer: Ok, sure. 
 agent: Carolyn Hill, there is no active reservation found under your name in our database. 
 customer: Ok, no issues. Anyways, thank you for the information. 
 agent: Thank you for contacting us.
no_reservation