You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: I need to book a ticket from HOU to SEA. Could you book a ticket?

ASSISTANT: Please provide your trip dates.

USER: Trip dates are Oct, 18 and Oct, 20.

ASSISTANT: Do you need any connection limit?

USER: I would prefer direct flight.

ASSISTANT: Do you need any other specifications?

USER: I would like to depart in the evening.

ASSISTANT: May I know your name?

USER: My name is Dennis Hill.

ASSISTANT: There are no flights available on your routes.

USER: Thank you.

ASSISTANT: Thank you for choosing us.