You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Kimberly Miller here. I need to change my recent reservation because my trip are postponed.

ASSISTANT: Sure, I will help you in changing the ticket.

USER: Thank you for your positive response.

ASSISTANT: Sorry there are no reservations found.

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

ASSISTANT: Thank you for reaching us.