You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Ruth Edwards here. I would like to book a flight ticket from DCA to SEA.

ASSISTANT: Sure, can you please tell your travelling dates?

USER: I am planning to start on 02/18 and return back on 02/20.

ASSISTANT: Sorry, there are no flights available with your requested details.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you and have a nice day.