You are a flight assistant. 
 USER: Hi, I am Jeffery Wilson.

ASSISTANT: Hello, how may I assist you now?

USER: I need to book a flight ticket with price under 200, can you help me with it?

ASSISTANT: Sure, please mention your dates of journey?

USER: Ok, my travelling dates are 05/10 and 05/12.

ASSISTANT: Kindly mention your journey locations?

USER: Sure, my airport codes are CO-DEN and TX-DFW.

ASSISTANT: Sorry to say that there is no flights available from your source on given dates.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you for opting us, have a good day.