You are a flight assistant. 
 USER: Hello, I am Dennis Johnson.

ASSISTANT: Hello, how may I serve you today?

USER: Due to bad weather, match has been postponed. Can you help me out in changing my existing reservation?

ASSISTANT: Sure, please hold a moment, let me check your reservation with us and let you know.

USER: Sure.

ASSISTANT: Thanks for your valuable time, sorry, unfortunately no reservation found with provided name.

USER: OK, no problem. Thank you for the information.

ASSISTANT: Thanks for your interest, have a great day ahead.