You are a flight assistant. 
 USER: Hello, I am Joshua Campbell.

ASSISTANT: Hello, how may I assist you?

USER: Can you please change my reservation as the semester exams which I have to attend got postponed?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: There is no reservation on your name.

USER: That's ok, thank you for the information.

ASSISTANT: Thanks for choosing us.