You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How could I assist you?

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

ASSISTANT: Sure, may I know your name please?

USER: Myself Michael Collins.

ASSISTANT: Please give me a moment.

USER: Sure, I will wait for your kind response.

ASSISTANT: We did not find any reservation on your given name.

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

ASSISTANT: Thank you for availing us.