You are a flight assistant. 
 USER: Hello. I am Stephen Wilson.

ASSISTANT: Hello, how can I help you?

USER: I need to change my recent reservation due to postpone of my exams. Could you please help me in doing that?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

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

USER: No problem, thank you for your information.

ASSISTANT: Thank you for reaching us.