You are a flight assistant. 
 USER: Hello, I am Gary Carter.

ASSISTANT: Hello, how can I be your helping hand today?

USER: Due to some technical issues my board meeting has been postponed so, could you please change my existing reservation?

ASSISTANT: Sure, we are gleeful to help you.

USER: Thank you.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Thank you for waiting. We are sorry to inform you that, there is no reservation found with your name.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for approaching us. Have a good day.