You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Stephen Hill.

ASSISTANT: How may I assist you Stephen Hill?

USER: My vacation trip has changed to another dates. So I would like to cancel my recent reservation. Will you please help me?

ASSISTANT: Yes, I will help on it. I found a reservation on your name and I have cancelled it.

USER: Thank you for your service.

ASSISTANT: Your most welcome.