You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Joseph Green here.

ASSISTANT: How can I assist you?

USER: Last week, I have booked a flight ticket to Dallas but due to some health issues, I'm planning to quit my trip. Can you please help me in cancelling my reservation?

ASSISTANT: Sure, I will help you with that. Green, we didn't found any reservation under your name in our database.

USER: Oh! My friend might have cancelled it already. Thank you for your time anyways.

ASSISTANT: Thank you for reaching us.