You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist 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 can change your reservation right now. Before that I need to know your good name please?

USER: I am Mark Clark.

ASSISTANT:  Thank you. Please stay online for a while, I will check your reservation status and let you know.

USER: Sure.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: No problem, thanks for the information.

ASSISTANT: Thank you for choosing us.