You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I am Michael Moore, in my previous reservation I gave wrong airport codes, so can you help me for changing my existing reservation?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait a moment to check your previous reservation.

USER: Ok, I will wait for your reply.

ASSISTANT: Sorry to inform you that, there is no reservation found with your name in our records.

USER: Oh! It's ok, no problem. Thank you for your services.

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