You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I would like to travel from DTW to DFW, can you book the flight ticket for me?

ASSISTANT: Sure. Please provide your journey dates.

USER: My preferable dates are from 11/25 till 11/27.

ASSISTANT: May I know your name please?

USER: Raymond Allen.

ASSISTANT: Allen, there are no flights available at this moment.

USER: That's ok.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your service.