You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: Due to some health issue, I am unable to travel now. Can you please change my existing reservation?

ASSISTANT: Sure, I will help you with that. May I know your name please?

USER: Sure, I am Nancy Mitchell.

ASSISTANT: Please wait for a minute.

USER: Ok, I will wait.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for reaching us.