You are a flight assistant. 
 USER: Hi. I am Joseph Campbell.

ASSISTANT: Hello, how may I assist you today?

USER: Will you please change my existing reservation as my plan to meet my friend got postponed?

ASSISTANT: Sure, please hold on a minute.

USER: Sure.

ASSISTANT: Thanks for your precious time, no active reservation was found on your name in the database.

USER: It's ok, not an issue. Thank you for the information.

ASSISTANT: Thank you for opting us.