You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, what can I do for you? Welcome to our travelling agency.

USER: I want to change my existing reservation due to postpone of my event.

ASSISTANT: Sure, could you please specify your name?

USER: I am Carolyn Taylor.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Taylor, there is no reservation found on your name to change.

USER: No issue. Thank you for your help.

ASSISTANT: Do you want any other help from me?

USER: No.

ASSISTANT: Thank you for your information.

USER: Welcome.