You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I need to change my existing reservation due to postpone of my document verification in office. Can you please help me?

ASSISTANT: Sure, I am here to help you with your concern.

USER: Ok.

ASSISTANT: Can you please help me with your name to check your reservation status?

USER: I am Samantha Phillips.

ASSISTANT: Please hold on a moment.

USER: Sure.

ASSISTANT: Samantha Phillips, no reservation has been found on your name in our database.

USER: Not a big deal, anyhow thank you very much for your service.

ASSISTANT: Thank you for choosing us.