You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, Good Evening.

USER: My name is Patrick Miller.

ASSISTANT: Patrick, how may I help you?

USER: Actually, I planned to attend an art show in Museum of Fine Arts in Boston, but due to some reasons, the show is postponed.

ASSISTANT: So would you like me to modify your existing reservation?

USER: Yes, can you help me out?

ASSISTANT: Sure, please hold on for a minute so that I can check with the details of your existing reservation.

USER: Sure, take you time.

ASSISTANT: Sorry, I could not find any ticket booked under your name to modify.

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you, have a good day.