You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I guide you today?

USER: My name is Margaret Walker and I want to change my reservation.

ASSISTANT: Ok, I am here to help you about that.

USER: Can you please help me? Thank you.

ASSISTANT: Please wait for a while.

USER: Take your time.

ASSISTANT: Sorry, no reservation found on your name to change the reservation.

USER: Thank you for the information.

ASSISTANT: Thank you for reaching us.