You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hi. How can I help you?

USER: I am Mark King. I would like to make a reservation from CO-DEN to TX-DFW.

ASSISTANT: May I know your journey dates?

USER: My journey dates are from May 10 to May 12.

ASSISTANT: Please wait for sometime, I will check and get back to you.

USER: OK.

ASSISTANT: Sorry, No flight were found on your details.

USER: Thank you for your service.

ASSISTANT: Thank you, Have a nice day.