You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Carol Hill.

ASSISTANT: Carol Hill, how may I assist you today?

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

ASSISTANT: Sure, I will help you. Please allow me a minute.

USER: Ok.

ASSISTANT: Carol Hill, I regret to inform you that there is no active booking done on your name.

USER: No problem, thank you.

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