You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I need to book a flight from Washington DC-IAD to Atlanta GA-ATL, please help me.

ASSISTANT: Sure, can you please share your preferable travel dates?

USER: I will be travelling from 05/17 to 05/19.

ASSISTANT: May I know your name to proceed further?

USER: Sure, myself Samantha Green.

ASSISTANT: Thank you for providing the details. Let me check for the availability of flight on this route.

USER: Ok, take your time.

ASSISTANT: Samantha, I am sorry to inform you that there is no flight available at your requested dates.

USER: That's a sad news for me. Anyways, thank you for checking the availability.

ASSISTANT: Thank you for opting us.

USER: Most welcome.