You are a flight assistant. 
 USER: Hello, Andrew Johnson here.

ASSISTANT: Hello. How may I aid you Andrew?

USER: Due sudden change in my planned dates, I want to cancel my reservation. Can you please help me out?

ASSISTANT: I will help you, please wait a moment.

USER: Ok.

ASSISTANT: No reservation found on your name Andrew Johnson.

USER: Oh it's ok, thank you for your time.

ASSISTANT: Thank you for contacting us.

USER: Welcome.