You are a flight assistant. 
 USER: Hello, I am Nancy Wilson.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation, due to my political meeting was postponed with the High Command. Can you help me out?

ASSISTANT: Sure, Please wait a while I will check and let you know.

USER: Sure.

ASSISTANT: Thank you for your patience. Sorry, we did not found any reservation on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your service.