You are a flight assistant. 
 USER: Hello, I am Rebecca Lopez.

ASSISTANT: Hello, how can I assist you now?

USER: I want to attend a press conference of my brother in Washington, can you help me with reservation?

ASSISTANT: Sure, I am happy to serve you. May I know your travelling dates?

USER: My depart is on 06/21 and return on 06/23.

ASSISTANT: Please assign you airport codes?

USER: OK, my origin is DTW and destination is IAD.

ASSISTANT: Do you have any other specifications?

USER: Yes, I need price under 500 with single connection.

ASSISTANT: Ok, please wait a couple of minutes.

USER: Sure.

ASSISTANT: Sorry there is no flight found on your connection details.

USER: No issues. Thank you, for the information.

ASSISTANT: Thanks for choosing us, have a great day.