You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I want change my existing reservation, due to some health issue. Can you help me?

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

USER: Thank you for accepting my request. Ok, I am Angela Robinson.

ASSISTANT: Please wait for a moment, while I check for the reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your given name to change it.

USER: Ok, not a problem. Thank you for your help.

ASSISTANT: Thank you for visiting us, we hope see you again.