You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: My appointment with doctor got postponed, so please change my existing reservation.

ASSISTANT: Sure, can I know your name?

USER: Sure, Cynthia King here.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: Ok, no worries at all. Thank you for your assistance.

ASSISTANT: Thank you for reaching us.