You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I need to book a ticket from ORD to DFW. Could you book a ticket?

ASSISTANT: Sure, can I know the travel dates please?

USER: Travel dates are July, 19 and July, 21.

ASSISTANT: May I know your name please?

USER: My name is Samantha Roberts.

ASSISTANT: Do you have any requirements?

USER: I prefer direct flight.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

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

USER: Thank you.

ASSISTANT: Thank you for approaching us.