You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to travel from DFW to IAD. Can you please make a reservation for me?

ASSISTANT: Sure, let me know your trip dates please?

USER: I want to travel on Aug 24 and intend to return on Aug 26.

ASSISTANT: May I know your connection limit?

USER: I need a direct flight.

ASSISTANT: Do you need any other preference?

USER: No.

ASSISTANT: Can I know your name please?

USER: Mark Hall.

ASSISTANT: Sorry to inform you that there are no flight services available on your given details.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thank you for contacting us.