You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Charles Lee.

ASSISTANT: How may I assist you?

USER: I would like to attend a flower festival at Washington, IAD so, can you please book a ticket with a direct flight?

ASSISTANT: Sure, may I know your travel dates?

USER: I want to travel on 03/28 and return back on 03/30.

ASSISTANT: Please share me your origin airport code.

USER: My origin is from Charlotte, CLT.

ASSISTANT: Sorry, there is no flight on your details.

USER: No problem, thank you for the information.

ASSISTANT: Thank you.