You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you now?

USER: I want to do some changes in my existing reservation. Can you help me for that?

ASSISTANT: Sure, I am happy to help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is Kathleen White.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no reservation found o your name in our database.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.