You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: Can you help me in changing my recent reservation?

ASSISTANT: Sure, for further proceeding to change your reservation. May I know your name?

USER: I am Charles Carter.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: We are regret to inform you that there is no active reservation on your name in our data.

USER: Its ok, thank you.

ASSISTANT: Thanks for reaching us.