You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I be at your service today?

USER: I would like to book a ticket from SFO to LGA.

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My travelling dates are from Oct, 25 to Oct, 27.

ASSISTANT: Do you have any other specifications?

USER: I would like to return in the afternoon.

ASSISTANT: Please help me with your name for booking.

USER: My name is Frank Lewis.

ASSISTANT: Sorry, no flights are available on your journey routes.

USER: Thank you.

ASSISTANT: Thank you for choosing us.