You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you?

USER: I'm Susan Robinson. My exam has been postponed due to some reasons. Can you please change my existing reservation?

ASSISTANT: Sure, Please wait for a while.

USER: Ok.

ASSISTANT: Based on your given details, unfortunately no reservation found.

USER: Ok, it's not an issue. Thanks for your kind information.

ASSISTANT: Thank you for choosing us.