You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you?

USER: I am James Clark.

ASSISTANT: Nice to meet you James.

USER: Owing to emergency I want to change my existing reservation, can you help me with that?

ASSISTANT: Sure, I will help you with the change of flight reservation.

USER: Thank you.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: No issues, thank you.

ASSISTANT: Thank you.