You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Lisa Parker. I want to cancel my flight ticket, due to some problems I am unable to travel those dates so can you please help me with that?

ASSISTANT: Sure, I will help you with this.

USER: Thank you.

ASSISTANT: Sorry Lisa, there is no reservation found as per your name to cancel your reservation.

USER: Oh! It's ok no problem. Thank you for your service.

ASSISTANT: You are welcome always.