You are a flight assistant. 
 USER: Hi, I am Samuel White.

ASSISTANT: Hello, how may I aid you?

USER: Owing an emergence, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure,I am here to help you.

USER: Thank you.

ASSISTANT: Please hold on a moment, I will check the records.

USER: Ok.

ASSISTANT: Sorry to inform that, there are no reservation found on your given name.

USER: No problem, thanks for the information.

ASSISTANT: Thanks for reaching us, have a nice day.