You are a flight assistant. 
 USER: Hi, I am Amy Collins.

ASSISTANT: Hello,. How may I help you?

USER: I want to attend a business meeting at Seattle, WA-SEA, can you please help me in booking a ticket from Washington, DC-IAD?

ASSISTANT: Please provide your travel dates in order to book a ticket.

USER: My travel dates are from 06/16 to 06/18.

ASSISTANT: Sorry, no flights found for your travel dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks.