You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: My name is Kevin White, can you please help me in  changing my existing reservation details?

ASSISTANT: Sure, please wait a moment I will check your details and proceed further.

USER: Ok, take your time.

ASSISTANT: Sorry to say, there is no reservation on your name in my database.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.