You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I am Sandra Parker, I want to change my recent reservation, help me in changing my reservation.

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation found with your name to change.

USER: Its ok, thank you for your assistance.

ASSISTANT: Thanks for opting us.