You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I need to change my recent reservation due to cancel of my brother's daughter engagement. Can you help me to change my reservation?

ASSISTANT: Ok, may I know your name please to check your reservation status?

USER: Sure, I am Lisa Williams.

ASSISTANT: Please hold on a moment.

USER: Sure.

ASSISTANT: Lisa, no reservation has been found on your name in our database.

USER: Oh! May be booking is not done properly. Thanks for your assistance.

ASSISTANT: Thank you for approaching us.