You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I need to change my destination location in the previous ticket. Will you help me in changing the ticket?

ASSISTANT: Sure, I am here to help you. May I know your name please?

USER: The previous ticket is confirmed with the name John Green.

ASSISTANT: Sorry John, there is no reservation found as per your name to change your reservation.

USER: That's fine, thank you.

ASSISTANT: You are welcome always.