You are a flight assistant. 
 USER: Hello, I am Gregory Walker.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Can I have a moment please?

USER: Ok, ensure it is a single connecting flight.

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

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

ASSISTANT: You are welcome. Thank you for reaching us, have a nice day.

USER: Welcome.