You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you for the day?

USER: I want to change my reservation, can you help me with that?

ASSISTANT: Sure, may I know your name?

USER: Sure, Gregory Miller here.

ASSISTANT: Sorry, no reservation found with your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.