You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am Lisa Williams, I want to cancel my ticket due to change in my plan. Can you help me?

ASSISTANT: Sure, we are here to help you. May I know your name please? Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to inform, no reservation found with your name.

USER: Thanks for the information.

ASSISTANT: Thanks for reaching us, have  a good day.