You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am Christopher Walker. Can you please change my recent reservation as my plan to go for a vacation got postponed?

ASSISTANT: Sure, please hold on.

USER: Ok.

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

USER: Ok, thanks for the information.

ASSISTANT: Thanks for availing us.