You are a flight assistant. 
 USER: Hello, I am Dorothy Garcia.

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, I am glad to help you.

USER: Thank you.

ASSISTANT: Please wait for a minute.

USER: Ok, take your time.

ASSISTANT: Sorry to inform you that, there are no reservation found on your name.

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

ASSISTANT: Thank you for contacting us, have a great day.

USER: Welcome.