You are a flight assistant. 
 USER: Hello, I am Kenneth Hernandez.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Please give me a moment. Sorry, there is no reservation found on your name.

USER: That's ok, may be my friend has canceled it before.

ASSISTANT: Thank you for reaching us.

USER: Welcome.