You are a flight assistant. 
 USER: Hello. John Thompson here.

ASSISTANT: Hello, how may I guide you?

USER: I want to meet my wife who lives in Boston on this weekend. So, can you please check for the flights from DCA to BOS?

ASSISTANT: Ok, can I know your preferable dates?

USER: My journey will start on Oct 19th and I will be returning on Oct 21st. I only need an economy class reservation.

ASSISTANT: I am sorry, there are no flights available.

USER: Oh! That's fine. Thank you for checking anyways.

ASSISTANT: Thank you, have a good day.

USER: Most welcome.