You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I guide you for today?

USER: I am Scott Taylor. I want to book a ticket from DCA to DFW, can you help me?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: My travel dates are June 28 and 30.

ASSISTANT: Do you have any class preferences?

USER: No.

ASSISTANT: Do you have any airline preferences?

USER: I am comfortable with any airline.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: I want to return in the evening.

ASSISTANT: Sorry, there are no flights available at your request.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for contacting us, have a nice day.