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, I am here to help you for this. May I know your name please?

USER: My name is Joseph Davis.

ASSISTANT: Please wait for a while.

USER: Ok, I will wait.

ASSISTANT: Sorry for inconvenience, no reservation is found under your name to change.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you very much for approaching our agency.