You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I would like to change my existing reservation because my brother marriage was postponed, can you help me?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name?

USER: Jessica Thomas.

ASSISTANT: There is no reservation found under your name to change.

USER: That's ok, thank you for giving information.

ASSISTANT: Thank you for opting us.