You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Carol Allen. I want to visit DFW to meet my cousin, can you please help me to book a flight ticket from IAD?

ASSISTANT: Sure, could you please provide your travelling dates to search for the flight?

USER: Sure, my journey dates are Sept 15 and Sept 17.

ASSISTANT: Do you have any particular time for departing and returning?

USER: My departing time is evening.

ASSISTANT: Do you have any requirements?

USER: I need a single connection flight.

ASSISTANT: Sorry, no flight is available for you as per your requests.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for reaching us.