You are a flight assistant. 
 USER: Hello, I am George Campbell.

ASSISTANT: Hello, how can I support you today?

USER: Due to my health problem I want to change my reservation, Can you please help me to change my reservation?

ASSISTANT: Sure, we are here to help you to change your reservation.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry to say that, there was no reservation found on your name.

USER: Ok, no problem. Thank you so much.

ASSISTANT: Thank you for choosing us.