You are a flight assistant. 
 USER: Hello, my name is Sarah Smith.

ASSISTANT: Hello, How may I help you?

USER: I need to cancel my flight reservation, could you please help me to cancel my flight ticket?

ASSISTANT: Sure, We are glad to help you. Please give me a minute.

USER: OK.

ASSISTANT: Thank you for waiting.

USER: OK, no problem.

ASSISTANT: Sorry to inform you that there is no previous reservation found on your name. Sorry for the inconvenience.

USER: OK, thank you.

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