You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I need to change my existing reservation as my plan to go for an historical tour got postponed. Can you please check if my reservation is active or not? If it is active, please change.

ASSISTANT: Sure, I will help you to change your reservation.

USER: Thank you.

ASSISTANT: Ok, may I know your name?

USER: My name is Edward Williams.

ASSISTANT: Please give me a moment.

USER: Ok, sure.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

USER: Ok, no problem. Anyways, thank you.

ASSISTANT: Welcome, have a nice day.