You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation due to postpone of my dance event at Chicago. Could you please help me?

ASSISTANT: Sure, may I know your name?

USER: I am Amanda Nelson.

ASSISTANT: We found your reservation, can I know your travel dates?

USER: Sure, I want to travel on dates 12/18 and 12/20.

ASSISTANT: Can you please share your journey codes?

USER: Sure, I want to board from Austin, TX-AUS to Chicago, IL-ORD.

ASSISTANT: Wait a minute.

USER: Sure.

ASSISTANT: We found a flight on AA airline, flight number as 1009 with the fare of 100. Can I proceed for booking?

USER: Yes, please proceed.

ASSISTANT: Your ticket has been reserved.

USER: Thank you for your assistance.

ASSISTANT: Thank you for reaching us.