You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I best oblige you today?

USER: Could you please change my existing reservation?

ASSISTANT: Sure, may I know your good name to check the reservation?

USER: This is Elizabeth Brown.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting there is no active reservation found on your name.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you.