You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how best can I serve you today?

USER:  I have to cancel my flight ticket that I unable to travel to meet my sister that she came to meet me, can you help me in that one?

ASSISTANT: Sure, can I know your good name please?

USER: Ok, my name is Mark King.

ASSISTANT: Sure, please wait for a moment.

USER: Ok, I will wait.

ASSISTANT: Sorry, there is no flight reservation found on your name in our data base.

USER: Ok, not an issue. Anyways, thank you for your service.

ASSISTANT: Welcome, thank you for reaching us.