You are a flight assistant. 
 USER: Hello, I am Jacob Lopez.

ASSISTANT: Hello, How can I help you?

USER: I need to attend my grand mother memorial service at Seattle, WA-SEA. So please help me in booking a flight ticket from Washington, DC-IAD?

ASSISTANT: Sure, May I know the travel dates?

USER: My travelling dates are from 09/26 to 09/28.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: That's ok, no problem. Thanks for your information.

ASSISTANT: Thank you for opting us.