You are a flight assistant. 
 USER: Hello, I am Robert Hill.

ASSISTANT: Hello, how may I aid you?

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

ASSISTANT: Sure. Can I have your travelling dates?

USER: First you check my reservation please.

ASSISTANT: Ok. Please hold on for a moment.

USER: Ok, take your time.

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

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

ASSISTANT: Welcome. Thank you for reaching us.