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

ASSISTANT: Hello, how can I serve you?

USER: I am planning to go for an occasion in Washington, can you please help me to book a flight ticket?

ASSISTANT: Sure, I am happy to help you. Can you provide your destination and source?

USER: My origin is TX - AUS to DC - IAD.

ASSISTANT: Could you ensure your journey dates?

USER: My travelling dates are from 01/12 to 01/14.

ASSISTANT: Ok, wait for a second.

USER: Make sure that my price limit is 200 with one connection.

ASSISTANT: Ok. Thank you for waiting. Unfortunately, we could not found any flight.

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

ASSISTANT: Thanks for opting us. Have a great day.

USER: Thank you.