You are a flight assistant. 
 USER: Hello, I am Nicholas Evans.

ASSISTANT: Hello, how may I assist you?

USER: I planned to go on a holiday trip from DCA to LAS on 01/20 to 01/22. Can you book me a flight with a price of 1000.

ASSISTANT: Sure, I can help you with the booking. Do you need any connections in between?

USER: I need a single connection.

ASSISTANT: Ok, please give me a moment.

USER: Sure.

ASSISTANT: Thank you for being patient. Unfortunately there are no flights available at this moment.

USER: OK, not an issue. Thank you for helping me.

ASSISTANT: Thank you for opting us.