You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to cancel my reservation due to health problem, can you help me?

ASSISTANT: Sure. May I know on whose name you have made the previous reservation?

USER: Myself Mark Martinez.

ASSISTANT: Mark, there is no reservation found with your details. Would you like to know anything else?

USER: No problem, thanks for checking.

ASSISTANT: Thank you for choosing us, have a great day.