You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

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

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

USER: Thanks, my name is Samuel Brown.

ASSISTANT: Ok, wait for a minute.

USER: Ok, I will wait.

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

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.