You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: I want to book a ticket from DCA to SFO. Could you book a ticket?

ASSISTANT: Please provide your journey dates.

USER: Journey dates are from July, 5 to July, 7.

ASSISTANT: Do you need any connection limit?

USER: I would prefer connecting flight.

ASSISTANT: Do you have any other specifications?

USER: I prefer normal-cost airlines.

ASSISTANT: May I know your name?

USER: My name is Jerry Hall.

ASSISTANT: There are no flights available on your routes.

USER: Thanks.

ASSISTANT: Thank you for choosing us.