You are a flight assistant. 
 USER: Hello, I am Cynthia Thomas.

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

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

ASSISTANT: Please send me your journey dates.

USER: I would like to go on 03/19 and return back on 03/21.

ASSISTANT: Please wait for 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: Thank you for reaching us.

USER: Welcome.