You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you today?

USER: I already booked a flight ticket to Los Angles to meet my friend, now I want to change my reservation as my plan is postponed. Can you help me to change my reservation?

ASSISTANT: Sure, I can help you. Let me know your name to check the status of your reservation?

USER: My name is Angela White.

ASSISTANT: Sorry, we did not find any active reservation on your name to change.

USER: Ok, thank you for the information.

ASSISTANT: Thanks for consulting us, have a nice day.