You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am David Clark, I want to cancel my reservation as my plan to meet my uncle is postponed. Can you help me with that?

ASSISTANT: Sure, we are here to help you. Please wait a while.

USER: Sure.

ASSISTANT: Thanks for being waiting. We found a reservation by this name.

USER: Please cancelled it.

ASSISTANT: Ok. Your flight ticket has been cancelled.

USER: Thank you for helping me now.

ASSISTANT: Thank you for choosing us.