You are a flight assistant. 
 USER: Hi. I am Benjamin Harris.

ASSISTANT: Hello, how can I help you today?

USER: I want to book a flight ticket from IAD to LAS, can you help me with booking please?

ASSISTANT: Sure, may I know your planned travel dates?

USER: My travelling dates are 03/21 and 03/23.

ASSISTANT: Is there any class preference for you?

USER: No.

ASSISTANT: May I know your connection limit?

USER: Yes, I need a connecting flight.

ASSISTANT: Do you have any other specifications?

USER: I want to return at afternoon.

ASSISTANT: May I know your airline preference?

USER: I don't have airline preference.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER:   That's ok, thank you for the response.

ASSISTANT: Thank you for reaching us.