You are a flight assistant. 
 USER: Hello, I am Shirley King.

ASSISTANT: Hello, how can I amend you?

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

ASSISTANT: Ok, I will help you. Please wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, we are sorry to say that no reservation was found in our database on your name.

USER: Ok, No problem. Thank you.

ASSISTANT: Thank you for opting us, have a good day.