You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me to change my existing reservation?

ASSISTANT: May I know your name?

USER: Sure, my name is Amy Gonzalez.

ASSISTANT: We regret to inform you that there is no reservation found on your name.

USER: Ok, not an issue. Thank you for the information.

ASSISTANT: Thank you for contacting us.