You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please help me in booking a flight ticket from DFW to ORD?

ASSISTANT: Sure, please share me your trip dates.

USER: I want to fly on Aug 16 and return on Aug 18.

ASSISTANT: Is there any class preferences for you?

USER: I am comfortable with any class.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a single connection.

ASSISTANT: May I know your airline preferences?

USER: I would like to prefer normal cost airline.

ASSISTANT: Please share me your other specifications.

USER: I would like to depart in the evening time.

ASSISTANT: For booking, we need your good name. Please provide it.

USER: Myself Jason Nelson.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for availing us.