You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I would like to change my existing reservation, can you help me in that?

ASSISTANT: Sure, I am here to help you with this. May I know your good name please?

USER: Sure, myself Paul Edwards.

ASSISTANT: Ok, wait for a moment please.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry Paul, there is no reservation found as per your name to change it in your database.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: You are welcome.