You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, I am here to help you. Can I know your name?

USER: Myself Jacob Gonzalez.

ASSISTANT: Ok, please give me a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that, there is no active reservation found with your name in our database.

USER: Not a big deal, anyhow thank you very much for checking the reservation status.

ASSISTANT: You are welcome. Thank you for choosing us.