You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER:  I want to cancel my recent reservation which I have done last week because my trip got cancelled. Please help me out with that.

ASSISTANT: How may I assist you now? Ok, please allow me to check with your previous booking.

USER: Sure, take your time.

ASSISTANT: May I know your good name please?

USER: Myself David Miller.

ASSISTANT: There is no flight available for your journey.

USER: It's ok, thank you.

ASSISTANT: Welcome.