You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Frank Martin here, can you please help me today with changing my reservation?

ASSISTANT: Please wait a while, I will check and inform you.

USER: Ok, take your time to check.

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

USER: Oh! That's very sad to hear from you. Anyways, thank you for checking.

ASSISTANT: Thank you for opting us.

USER: You are most welcome.