You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Margaret Carter.

ASSISTANT: How can I aid you?

USER: I need to change my 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 it.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: That's Ok, thanks for your response.

ASSISTANT: Anyways, thank you for reaching us.