You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I'm Sarah Smith. Can you please help me in cancelling my recent reservation?

ASSISTANT: Sure Sarah, give me a moment.

USER: Sure.

ASSISTANT: I am sorry Sarah, I didn't find any reservation regarding your details.

USER: OK, that's not a problem.

ASSISTANT: Sorry, there is a reservation with your details. Thank you for contacting us. Your reservation has been cancelled successfully.

USER: Thank you for your help.