You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Actually, I need to change my existing reservation which is done due to my health issue, can you please help me out?

ASSISTANT: Sure, I am here to help you out. May I know your name please?

USER: Sure, my name is Sarah Edwards here.

ASSISTANT: Wait a moment please. Sarah Edwards, we regret to inform you that there is no reservation found on your name in our records.

USER: Sure, I will wait. Ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your information.