You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Can you help me to change my recent reservation?

ASSISTANT: May I know your name?

USER: Nicholas Thompson here.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: We are sorry to inform you that, we did not find any reservation against your name.

USER: That's ok, thank you.

ASSISTANT: Thank you.