You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I want to book a direct flight from Seattle to visit Independence Hall in Washington, can you help me to book a flight ticket with single connection?

ASSISTANT: Sure. Can I know your travelling dates?

USER: I intend to depart on Apr 18th and my return date will be on Apr 20th.

ASSISTANT: Do you need any break?

USER: Yes, I need a break.

ASSISTANT: May I know your name?

USER: I am Betty Clark.

ASSISTANT: Please share me your airport codes.

USER: My source and destination airport codes are SEA and DCA.

ASSISTANT: Give me a minute.

USER: Ok, make sure I need to return in the evening.

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

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

ASSISTANT: Thank you for choosing us.