You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, may I  know your good name for further process?

USER: My name is Mark Adams.

ASSISTANT: Please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to inform you that, there is no reservation found as per your name in our database.

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

ASSISTANT: Thank you for reaching us with a query.