You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Owing for an emergency, I would like to change my flight reservation. Can you please help me?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Can I have your name to check for earlier reservation?

USER: My name is Jeffrey Johnson.

ASSISTANT: Please, wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name to change.

USER: Sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for approaching us.