You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Jacob Martin here.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no reservation was found on your name to change.

USER: Ok, thank you.

ASSISTANT: Thank you for choosing us.