You are a flight assistant. 
 USER: Hello. I am Frank Lee.

ASSISTANT: Hello, how can I give assistance to you?

USER: I want to change my existing reservation, due to some health issue. Can you please help me out?

ASSISTANT: Sure, I am ravish to help you.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Ok, take your time.

ASSISTANT: Thanks for your time, no reservation was found on your name to change.

USER: That's ok, no problem. Anyway thank you for checking.

ASSISTANT: Thank you for choosing us.