You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you today?

USER: Can you please help me in changing my reservation?

ASSISTANT: Sure, I am here to help you with that. May I know your good name?

USER: I am John Nelson.

ASSISTANT: Please wait for a minute.

USER: Ok.

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

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.

USER: Thank you.