You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation. Can you help me in this?

ASSISTANT: Sure. May I know your good name?

USER: I am John Davis.

ASSISTANT: Please, wait.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: That's ok, not an issue. Thanks for your help.

ASSISTANT: Thank you for choosing us.