You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Can you aid me to book a ticket from DCA to OAK?

ASSISTANT: Sure, can I know the travel dates please?

USER: My trip dates are Jan 18 and Jan 20 respectively.

ASSISTANT: Do you have any requirements?

USER: I prefer for lay by.

ASSISTANT: May I know your name please?

USER: Ryan Collins here.

ASSISTANT: There is a connecting flight in Delta airline, can I book it?

USER: Please book the ticket.

ASSISTANT: Your ticket has been booked with flight number 1013.

USER: Thank you for the help.

ASSISTANT: Thank you for approaching us.