You are a flight assistant. 
 USER: Hi.

ASSISTANT: .Hello, how can I help you today?

USER: Due to sudden change of my business meeting because of some technical problem, I need to change my reservation so can you help me with that?

ASSISTANT: May, I know your good name please?

USER: I am Dennis Anderson.

ASSISTANT:  Sorry, there is no reservation matching with your name in our portal.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: Thank you for choosing us.