You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation due to postpone of my event. Can you please help me?

ASSISTANT: Sure, may I know your name?

USER: Sure, I am Elizabeth Turner.

ASSISTANT: There was no reservation found on your name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for choosing us.