You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I would like to book a ticket from IAD to DFW, can you please help me out?

ASSISTANT: Sure, I am here to help you. Can you please share your travel dates?

USER: I am travelling on these dates July 13th and 15th.

ASSISTANT: Do you have any connection limit?

USER: I need a single connected flight.

ASSISTANT: May I know your class preference?

USER: I prefer economy class.

ASSISTANT: Do you have any other requirements?

USER: I don't have any other preferences.

ASSISTANT: May I know your name to proceed further?

USER: Sarah Jones here.

ASSISTANT: Sorry, there are no flights in this route as per your travelling details.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for choosing us.