You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I hep you?

USER: I am Joseph Carter. My planned trip got postponed unexpectedly, so I need to change my travel dates. Can you please help me in changing?

ASSISTANT: Sure, I will help you in changing your reservation.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Ok, I will wait for your reply.

ASSISTANT: Sorry, there are no reservations found.

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

ASSISTANT: Thank you for choosing our services.