You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your good name please?

USER: I am Michelle Johnson.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is no reservation found in your name to change.

USER: Not a problem, thank you.

ASSISTANT: Thank you for choosing us.