You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: Can you please help me to cancel my  previous ticket? Because I had some other work so that I have cancelled the trip.

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is Helen Campbell.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: It's ok, not a problem with that. Thank you for your help.

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