You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Christopher Thomas. I want to celebrate my sister marriage in Atlanta botanical Garden at Atlanta, GA - ATL. Can you please help me with book a single connection of flight?

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

USER: I have planned my travel dates are 12/09 to 12/11.

ASSISTANT: Can you please share your source airport code?

USER: My source airport code is from Washington DC - IAD.

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

USER: OK, no problem. Thanks for your information.

ASSISTANT: You are welcome.