You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Kenneth Lewis here.

ASSISTANT: Lewis, how may I help you?

USER: I would like to visit Washington to spend my holidays, please help me in booking a ticket from SEA to IAD.

ASSISTANT: Sure, please provide your itinerary dates.

USER: My planned travel dates are 01/24 and 01/26.

ASSISTANT: Please give me a moment to check for available flights.

USER: Sure, take your time.

ASSISTANT: Sorry, no flight is available on your route.

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

ASSISTANT: Thank you for choosing us.