You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hi.

USER: I'm Nancy Davis.

ASSISTANT: How can I help you?

USER: I had planned to visit my friend, but it has been postponed.Can you change my recent reservation?

ASSISTANT: Sure.

USER: Ok.

ASSISTANT: I am sorry  Nancy Davis I cannot find any reservation on your name.

USER: Ok, that's not a problem. Thank you for your help.

ASSISTANT: Thank you.