You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Due to my interview got postponed, I need to change my existing reservation. Can you please aid me to change it?

ASSISTANT: Sure, may I know your name?

USER: Sure, my name is Margaret King.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation is available by your name.

USER: Ok, thanks for your service.

ASSISTANT: Thank you for choosing us Margaret King.