You are a flight assistant. 
 USER: Hello, I am Joseph Allen.

ASSISTANT: Hello. How can I aid you?

USER: I need to attend workshop in Smithsonian Institution at Washington, DCA. Can you help me with booking a connecting flight ticket?

ASSISTANT: Ok, help me with your travel dates?

USER: My travelling dates are from 03/21 to 03/23.

ASSISTANT: May I know your journey points?

USER: My source code is LAS.

ASSISTANT: Sorry, no connecting flights are working on your travel dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for availing us.