You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Stephen Young here.

ASSISTANT: How can I help you?

USER: I am planning to participate in singing competition in IAD. Can you book a flight ticket from SEA?

ASSISTANT: Could you please provide your travelling dates?

USER: It's 01/28 to 01/30.

ASSISTANT: There is a flight available with price 200 and flight number is 1009, would you like to proceed?

USER: Yes, please proceed my ticket booking.

ASSISTANT: Your booking is confirmed.

USER: Thank you for your assistance.

ASSISTANT: You are welcome.