You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: My name is William Lopez. Actually, I booked a ticket to NYC for a music concert but due to bad weather the trip is cancelled.

ASSISTANT: Ok, so would you like me to change your existing reservation?

USER: Yes, help me out.

ASSISTANT: Ok, please hold on for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry, I could not find any ticket booked with your name.

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

ASSISTANT: Thank you, have a great day.