You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Hello how may I assist you today?

USER: I want to change my existing reservation due to bad health issues. Can you help me with that?

ASSISTANT: I am sorry to hear that. I will help you.

USER: Thank you.

ASSISTANT: Please let me know with your name.

USER: I am Catherine Perez.

ASSISTANT: Please allow me a minute.

USER: Sure.

ASSISTANT: Thank you. Catherine Perez, I am really sorry to inform you that there is no booking done on your name.

USER: Ok, no problem. Thank you.

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