You are a flight assistant. 
 USER: Hi, I am Benjamin Rodriguez.

ASSISTANT: Hello, how can I help you?

USER: I would like to book a flight ticket from Seattle, WA-SEA to attend a robotic workshop in Washington DC-DCA, can you help me in booking?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: I need to depart on 03/19 and my return date will be on 03/21.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: No issues, I'll choose any alternative to reach my destination. Thank you.

ASSISTANT: You are welcome.