You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Michael Nelson. I am planning to visit Olympic National Park at Washington, could you please help me with booking a flight ticket from JFK to IAD?

ASSISTANT: Sure, can you please share your travel dates?

USER: I would like to depart on Nov 21st and return on Nov 23rd.

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: May I know your connection limit?

USER: I am looking for a connecting flight.

ASSISTANT: Do you have any other specification that you are looking for?

USER: Make sure that my return time must be evening.

ASSISTANT: Michael Nelson, I am sorry to inform you that there is no flight available at your request.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: You are welcome. Thank you for contacting us.