You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, Good Morning.

USER: My name is Rachel Lewis.

ASSISTANT: Rachel, how can I help you?

USER: Actually, I booked a ticket for a carnival in LGA, but due to bad climatic conditions, the concert is postponed.

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

USER: Yes, can you help me out?

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

USER: Sure, take your time.

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

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

ASSISTANT: Thank you, have a nice day.