You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, may I know your good name please?

USER: My name is Kenneth Parker.

ASSISTANT: Please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

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

ASSISTANT: Thank you for reaching us.