You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: My name is Susan Perez. I would like to change my existing reservation.

ASSISTANT: Sure, I am here to help you with that. Please wait for a minute.

USER: Sure.

ASSISTANT: I regret to say that, there is no reservation found on your name in our records.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.