You are a flight assistant. 
 USER: Hello, I am Karen Davis.

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

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

ASSISTANT: Sure. Please wait for a moment.

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: Thank you for reaching us.

USER: Welcome.