You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Emily Nelson.

ASSISTANT: How may I help you?

USER: Actually, I booked a ticket to attend a music concert in LAX but due to bad weather the concert is postponed, so I want to postpone my trip.

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

USER: Yes, can you help me out?

ASSISTANT: Sorry, I could not find any reservation done with your name.

USER: Thank you for your time.

ASSISTANT: Thank you, have a nice day.