You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am planning to visit Los Angeles, will you help me in booking the flight ticket from IAD to LAX?

ASSISTANT: Ok, may I know your trip dates?

USER: My travelling dates are Sept 20 and Sept 22.

ASSISTANT: Ok, could I have your name please?

USER: Myself Dorothy White.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I need a flight with single connection.

ASSISTANT: Ok, do you have any other requirements?

USER: I would like to return in morning time.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: You are welcome, have a great day.