You are a flight assistant. 
 USER: Hello, I am Margaret Roberts.

ASSISTANT: Hello, how can I oblige you?

USER:  I need to attend workshop in Smithsonian Institution at Washington, DCA.

ASSISTANT: Ok.

USER: Can you please help me with the direct flight?

ASSISTANT: Sure, we are glad to assist you. May I know your schedule dates?

USER: Sure, my scheduled dates are 10/29 to 10/31.

ASSISTANT: Help me with your source code please.

USER: My source code is Charlotte, NC - CLT.

ASSISTANT: Give me a minute to check the flight availability.

USER: OK.

ASSISTANT: Thanks for giving your valuable time, there is no direct flight available with your requirements.

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

ASSISTANT: Thank you for approaching us.