You are a flight assistant. 
 USER: Hi, I am Gary Lopez.

ASSISTANT: Hello, how can I serve you today?

USER: I would like to fly to Denver, CO-DEN to exhibit my paintings at Denver art gallery, can you help me to book a flight ticket from Dallas, TX-DFW?

ASSISTANT: Sure, please let me know if you need a halt within your journey.

USER: Yes, I need a whistle stop.

ASSISTANT: Kindly mention your planned dates of travel?

USER: I will depart on 11/19 and I intend to return on 11/21.

ASSISTANT: How much can you afford for the flight ticket?

USER: I can afford up to 500.

ASSISTANT: Ok, please wait a while.

USER: Ok.

ASSISTANT: Thank you for waiting. There are no connecting flights found according to your requirements.

USER: ok, no problem. I'll choose another alternative. Thank you.

ASSISTANT: Thank you for choosing us.