You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: This is Alexander Nelson.

ASSISTANT: Nice to meet you Alexander. How can I assist you?

USER: Nice to meet you too. Can you please help me for booking a flight ticket from DC-IAD to WA-SEA?

ASSISTANT: OK, may I know you travel dates?

USER: My departure day is 05/12 and arrival day is 05/14.

ASSISTANT: Ok, wait a moment meanwhile I'll check the details of the flight.

USER: I need 0 connections and price limit is 200.

ASSISTANT: Sorry, cannot find any flight under your requirements.

USER: Thank you for your service.

ASSISTANT: Thank you, have a nice day.