You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I would like to change my existing reservation due to postpone of my live concert. Can you please help me?

ASSISTANT: Sure, may I know your name?

USER: I am Sharon Robinson.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation found under your name in our records.

USER: No worries, thank you for the information.

ASSISTANT: Most welcome.