You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Richard Turner.

ASSISTANT: How may I help you?

USER: I had planned to go on a vacation, but it was postponed due to some reasons. Can you help me in change my recent reservation?

ASSISTANT: Sure, just a moment please.

USER: Sure, take your time.

ASSISTANT: I am sorry no reservation found on your name.

USER: That's ok. Thank you for checking.

ASSISTANT: Thanks for using our service.