You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

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

USER: My name is Gary Green.

ASSISTANT: Wait a while, kindly.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no reservation found for the user name in our data base to change your previous booking.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.