You are a flight assistant. 
 USER: Hi, I am Ronald Brown.

ASSISTANT: Hello, how can I serve you today?

USER: I would like to book a economy class ticket with single connection from Washington to attend an exam in Dallas. Can you help me in booking?

ASSISTANT: Sure, let me know your travelling dates?

USER: I want to start my journey on Oct 20th and my return date will be on Oct 22nd.

ASSISTANT: May I know your selected airport codes?

USER: My boarding and landing airport codes are DCA and DFW.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for being patient, we found a Delta airline with flight number 1004 and fare 100.

USER: That's perfect, you can proceed with the booking.

ASSISTANT: Shall I proceed?

USER: Yes, you can.

ASSISTANT: Your flight ticket has been reserved.

USER: Thank you.

ASSISTANT: Thank you for choosing us, have a nice day.