You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Mark King.

ASSISTANT: How may I assist you at this moment?

USER: I would like to cancel my reservation as I have my brother's housewarming, can you please help me out?

ASSISTANT: Sure, I can assist you with that.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Sure, take your time.

ASSISTANT: Sorry for the trouble, there is no ticket booking found on your name to cancel.

USER: Ok no problem, thank you for your services.

ASSISTANT: You are welcome. Thank  you for contacting us.