You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am planning to travel from DCA to IAD. Can you please help me to book a ticket?

ASSISTANT: Sure, please share your planned travel dates?

USER: I want to start on Oct 25 and return on Oct 27.

ASSISTANT: Let me know your connection limit?

USER: I need a direct flight.

ASSISTANT: Any other preferences?

USER: I want to depart in the evening.

ASSISTANT: Can I have your name please?

USER: Jeffrey Lopez here.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, no flights found with your given details.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for opting us.