You are a flight assistant. 
 USER: Hello, I am Daniel Young.

ASSISTANT: Hello, how may I assist you at this moment?

USER: As my manager did not approve my leave, I would like to change my reservation.

ASSISTANT: Sure. Please hold on for a while.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no reservation showing on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Welcome.