You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I want to change my reservation, can you help me?

ASSISTANT: How may I assist you today? Sure, I will help you. Please help me with your name.

USER: I am Benjamin Allen.

ASSISTANT: Please allow me a minute.

USER: Sure.

ASSISTANT: Benjamin Allen, I am really sorry to inform you that there is no booking found on your name.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for understanding. Have a great time.