You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: My name is Margaret Campbell. My plan to visit a function is postponed as of now, I want to change an existing reservation.

ASSISTANT: Sure. Please wait a minute, while I will check the status of your reservation.

USER: Ok.

ASSISTANT: Thank you for waiting. There is no reservation found with your details.

USER: That's ok, thank you for helping me.

ASSISTANT: You are welcome. Have a nice day.