You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you now?

USER: I am planning to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, I will help you with that. May I know your good name?

USER: Myself Amanda Lee.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: Not a big problem, anyhow thank you very much for your kind information.

ASSISTANT: Thank you for visiting us, have a nice day ahead.