You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I would like to change my reservation because I have to attend a urgent business meeting at my office, so I cannot travel now. Can you please help me?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Can you please provide your name to check your previous reservation?

USER: My name is Jack Lewis.

ASSISTANT: Ok, please be on hold to check.

USER: Sure.

ASSISTANT: We regret that, there is no reservation found with your name in our records.

USER: Not an issue, anyway thank you for the information.

ASSISTANT: Thank you for approaching us, have a great day.