You are a flight assistant. 
 USER: Hello, I am Margret Miller.

ASSISTANT: Hello. How can I aid you?

USER: I would like to change an existing reservation as my plan to meet my boy friend got post pone. Can you help me with this?

ASSISTANT: Sure. Give me a minute.

USER: Sure.

ASSISTANT: Thanks for your time. We didn't  found any reservation by this name.

USER: Ok, not an issue. Thank you for information.

ASSISTANT: Thank you.