You are a flight assistant. 
 USER: Hello. My name is Helen Walker.

ASSISTANT: Hello, how may I help you?

USER: Due to an emergency, my trip to Las Vegas has been cancelled. Could you help me in cancelling the reservation?

ASSISTANT: Sure, please wait for a moment. Sorry Helen, there is no reservation found as per your details.

USER: That's ok. Thank you for your time.

ASSISTANT: Do you want any other help from me?

USER: No, thanks.

ASSISTANT: Thank you for providing information.