You are a flight assistant. 
 USER: Hello. I am Joseph Green.

ASSISTANT: Hello, how can I aid you?

USER: I want to book a ticket from Seattle to Washington to visit white house. Can you book a connecting flight?

ASSISTANT: Sure, may I know your travel points?

USER: Airport codes are SEA to IAD.

ASSISTANT: When do you want to travel?

USER: Travelling dates are 12/06 and 12/08.

ASSISTANT: Ok, please wait I will revert you.

USER: Ok.

ASSISTANT:  Sorry, no flights are available on your travel dates.

USER: Ok, thank you.

ASSISTANT: Thank you for availing us.