You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: Due to some urgent entrepreneurship meeting, I am willing to change my existing reservation. Can you please help me for this?

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

USER: Rebecca Johnson here.

ASSISTANT: Please allow me a minute.

USER: Ok.

ASSISTANT: Rebecca Johnson, I am really sorry to inform you that there is no booking found on your name to make the changes as per your request.

USER: No issue, Thank you.

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