You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Can you help me booking a flight ticket from DTW to DEN?

ASSISTANT:  May I know your preferred dates to travel?

USER: I will start on 09/21 and return on 09/23.

ASSISTANT: Do you need either direct flight or connecting flight?

USER: I am comfortable with any flight.

ASSISTANT: May i know your airline preference?

USER: I am looking for a normal cost.

ASSISTANT: Can you please tell me your name?

USER: I am Gregory Mitchell.

ASSISTANT: Ok, do you have any other specifications?

USER: No.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there are no flights found with your requirements.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.