You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I am Brenda Brown. I want to visit White House at Washington, Can you please book a ticket to DCA?

ASSISTANT: Sure, kindly mention your travel dates?

USER: My depart is on 09/28 and return is on 09/30.

ASSISTANT: Can you please provide me your source airport code?

USER: Source code is Chicago, ORD.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no flights found with your requirement.

USER: No problem.

ASSISTANT: Thanks for reaching us, have a good day.

USER: Thank you.