You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Dennis Wilson.

ASSISTANT: How can I serve you?

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.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting.

USER: Ok.

ASSISTANT: No reservation found on your data.

USER: Not a problem. Thanks for the information.

ASSISTANT: Thank you.