You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change my existing reservation due to some issues, can you please help me with that?

ASSISTANT: Sure, I will help you. Please help me with your name.

USER: Sure, I am Kenneth Harris.

ASSISTANT: Please allow me a minute to check for your booking details.

USER: Sure.

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

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for understanding.