You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: My name is Kimberly Mitchell, I want to change my reservation as my trip is postponed. Can you change my reservation?

ASSISTANT: Sure, I am here to help you out.

USER: Thank you.

ASSISTANT: Kimberly Mitchell, there is no active reservation with your name to change your reservation.

USER: Ok, thank you for the information.

ASSISTANT: You are welcome, thank you for reaching us.