You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how could I aid you?

USER: There is art museum in Chicago but due to some reason I can not go, can you change the reservation to other day? Can you please help me to change it?

ASSISTANT: Can I know your name please?

USER: Sure, my name is Richard Anderson.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: We are sorry to inform your that there is no reservation found with your given name.

USER: Ok, no problem. Thanks for your help.

ASSISTANT: Thank you for opting us.