You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I'm William Clark. My holiday trip has been postponed. So, I would like to change my recent reservation which is under my name.

ASSISTANT: Please give me a minute, I will find your existing reservation status.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for contacting us, have a nice day.