You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: David Phillips here.

ASSISTANT: How can I help you?

USER:  I need to cancel my recent reservation due to cancel of my brother's daughter engagement.

ASSISTANT: Just a moment please.

USER: Sure.

ASSISTANT: I am sorry no reservation found on your name.

USER: That's ok, Thank you.

ASSISTANT: Thank you for choosing us.