You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: Could you please change my existing reservation due to postpone of my trip?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can I have your name to proceed further?

USER: My name is Catherine Jones.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your time, sorry no reservation found on your name.

USER: Not a problem, thanks for checking.

ASSISTANT: Thank you for reaching us.