You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am William Jackson. I would like to postpone my existing reservation due to postpone of my meeting, can you help me in booking a ticket?

ASSISTANT: Sure, I am here to help you.

USER: Ok.

ASSISTANT: Please stand by I will get back to you,.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry to say no reservation found on your name.

USER: Ok, no worries at all.

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

USER: Thank you.