You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you now?

USER: I want to change my existing reservation, due to my exams has been postponed.

ASSISTANT: Ok.

USER: Can you help me to change my reservation on the name of Anthony Evans?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Give me  a minute to check the reservation on your name.

USER: Sure.

ASSISTANT: Thanks for your precious time. There is no reservation found on your name.

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

ASSISTANT: Thank you for approaching us.