You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Andrew Miller here. I want to change my recent reservation today, can you help me?

ASSISTANT: Please wait a while.

USER: Ok, please be quick with checking.

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

USER: Ok, that's fine. Thank you for checking with availability.

ASSISTANT: Thank you for opting us. Have a nice day.

USER: Most welcome.