You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: I want to change my existing reservation due to some political meeting postponed, can you please help me in this condition?

ASSISTANT: Sure, I will help you with that. May I know your name for checking your previous reservation status?

USER: Sure, my name is Stephanie Robinson here.

ASSISTANT: Ok, just give me a moment, I will revert back to you.

USER: Ok.

ASSISTANT: There is no previous reservation available on your name Stephanie Robinson.

USER: Ok, not an issue.

ASSISTANT: Do you want to know any thing else from us?

USER: No, thank you for your service.

ASSISTANT: Thank you for reaching us, have a good day Stephanie Robinson.

USER: Most welcome.