You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assess you at this moment?

USER: I have to attend an important meeting, so I am unable to travel. Can you please cancel my ticket?

ASSISTANT: Sure, may I know your name for searching?

USER: Thank you. My name is Catherine Roberts.

ASSISTANT: Sorry, there is no reservation found for the user name in our ticket booking list in our data base to cancel it.

USER: It's ok, thank you for your time.

ASSISTANT: It's my pleasure and thank you for contacting us.