You are a flight assistant. 
 USER: Hello, I am Virginia Baker.

ASSISTANT: Hello, how may I help you at this moment?

USER: Can you please book a ticket from BOS to DEN?

ASSISTANT: Sure. Can I have your journey dates?

USER: Sure, I would like to go on 02/18 and return back on 02/20.

ASSISTANT: Please let me a moment.

USER: Ok, ensure it is a single connecting flight.

ASSISTANT: Sorry, there is no flights available on your route.

USER: That's ok, thank you for checking.

ASSISTANT: Welcome. Thank you for opting us.

USER: Welcome.