You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: My name is Christopher Harris. Due to an emergency, I would like to change my reservation.

ASSISTANT: Sure, wait for a minute.

USER: OK.

ASSISTANT: Sorry Harris, no reservation found on your name.

USER: That's ok. Thank you for your time.

ASSISTANT: Do you want any other help?

USER: No, thank you.

ASSISTANT: Ok, thank you for approaching us.