You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, How may I help you?

USER: I am Helen Hill. I want book a flight ticket from Washington, IAD to SEA.

ASSISTANT: May I know the travel dates?

USER: My travel dates are 08/04 and 08/06.

ASSISTANT: Sorry, No flights found with your preferable dates. Thank you for opting us.

USER: Ok, not a problem. Thanks for your information.