You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: Sure, I can help you. May I know your name?

USER: I am Joshua Smith.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT:  Sorry, we couldn't find a reservation on your name to change.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.