You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Please help me to change an existing reservation as my tournament  got postpone due to bad weather conditions.

ASSISTANT: Ok, may I know your name to check for your reservation?

USER:  I am Dennis Walker.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no reservations been found on your name to proceed.

USER: No issues, thank you for your information.

ASSISTANT: Thank you for choosing our agency, have a nice day.