You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Could you please change my existing reservation due to postpone of my board meeting?

ASSISTANT: Sure, may I know your name please?

USER: My name is George Thomas.

ASSISTANT: I am sorry no reservation found on your name.

USER: Not a problem, thank you for checking.

ASSISTANT: Thank you for choosing us.