You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my recent reservation because of some work. Can you please help me out?

ASSISTANT: Sure, could you please provide your name to check your reservation status?

USER: Sure, my previous reservation is on the name of Robert Davis.

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

USER: Sure.

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

USER: Ok, no problem. Thank you for your information.

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