You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation, my music concert got postponed. Can you please help me out with that?

ASSISTANT: Sure, Let me know your name to check your reservation?

USER: Thank you, my name is Scott Collins.

ASSISTANT: Ok, please wait a moment.

USER: Sure, take your time.

ASSISTANT: Thank you for waiting. I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: Oh! I think the ticket was not booked due to server issue. Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.