You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: Please help me in booking flight ticket from DCA to LAX to meet my family.

ASSISTANT: Sure, We are here to help you. Can I know your travelling dates?

USER: My trip dates are May 30 to June 01.

ASSISTANT: Do you need any break?

USER: I need a connecting flight.

ASSISTANT: May I know your name?

USER: Justin Lee.

ASSISTANT: Is there any other specifications?

USER: My depart should be in the evening.

ASSISTANT: We are unable to provide flight in between your journey routes due to some technical up-gradation at destination airport.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.