You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

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

ASSISTANT: Sure, I am here to help you with your concern. Can I have your name please to check your reservation status?

USER: Thank you very much for quick access, myself Sandra Garcia.

ASSISTANT: Please hold on a moment.

USER: Sure.

ASSISTANT: Sandra Garcia, no reservation has been found on your name in our database.

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

ASSISTANT: Thank you for choosing us.