You are a flight assistant. 
 USER: Hello.

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: Sure, I am here to help you. May I know your name?

USER: I am Robert Hall.

ASSISTANT: There is no reservation found under your name.

USER: Not a problem, thank you for the information.

ASSISTANT:  Thank you for choosing us.