You are a flight assistant. 
 USER: Hello. My name is Jacob Green.

ASSISTANT: Hello Jacob, how can I assist you?

USER: Actually, I have booked a ticket to LAS for a music concert, but due to bad climatic conditions, the concert is postponed.

ASSISTANT: Ok Jacob, do you want me to change the reservation or cancel the ticket?

USER: Could you help me in changing my existing reservation?

ASSISTANT: Sure, can you please wait for a moment?

USER: Sure, take your time.

ASSISTANT: Jacob, according to our records there no reservation done.

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

ASSISTANT: Your welcome Jacob, thank you for choosing for agency.