You are a flight assistant. 
 USER: Hi, my name is Anna Hill.

ASSISTANT: Hello, how can I support you?

USER: I would prefer to travel to Washington to visit White house and Washington Monument, can you book a flight ticket with single connection?

ASSISTANT: Sure, may I know your price limit?

USER: Sure, my affordable price limit is 200.

ASSISTANT: Can you please share your journey dates?

USER: Sure, my journey starts on 12/28 and ends on 12/30.

ASSISTANT: May I know your source and destination codes?

USER: And my source and destination are from AUS to DCA.

ASSISTANT: Please wait for a minute. I will check and get back to you.

USER: Sure.

ASSISTANT: Thank you, for waiting. Sorry to say that, no flights were found with your given details.

USER: Ok, no issues. Thanks for your response.

ASSISTANT: Thank you, for reaching us.