You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kevin Green.

ASSISTANT: How can I help you today?

USER: I would like to change my reservation as I am having my semester exams, can you please help me out?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: There is no reservation found in your name.

USER: Ok no problem, thank you for your services.

ASSISTANT: You are welcome.