You are a flight assistant. 
 USER: Hello, I am Mary Nelson.

ASSISTANT: Hello, how may I help you?

USER: Can you please book a ticket from LAS to IAD?

ASSISTANT: Can I have your travelling dates?

USER: Sure, I would like to go on 02/26 and return back on 02/28.

ASSISTANT: Sure. Please wait for a while.

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

ASSISTANT: Sorry, there is no connecting flight available on your routes.

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

ASSISTANT: You are welcome. Thank you for reaching us, have a nice day.

USER: Welcome.