You are a flight assistant. 
 USER: Hello, I am Susan Thompson.

ASSISTANT: Hello, how may I assist you?

USER: I want to visit 16th street mall at Denver, please book a connecting flight.

ASSISTANT: Sure, may I know your price limit to book a ticket?

USER: I need the ticket within price 500.

ASSISTANT: Ok, what dates you would like to travel?

USER: I want to fly on 12/28 and return on 12/30.

ASSISTANT: May I know your airport codes?

USER: My origin airport code is TX- DFW and Dest airport code is CO- DEN.

ASSISTANT: Ok, there is a flight 1004 in Southwest airline matching your requirements with price 300. Shall I proceed with this airline?

USER: Please proceed with booking.

ASSISTANT: Ok, your ticket has been booked.

USER: Thank you for the reservation.

ASSISTANT: Thanks for reaching us. Have a safe journey!.