You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your name?

USER: Sure, my name is Christine Evans.

ASSISTANT: How can I provide assistance you?

USER: I have to attend the art exhibition at National Gallery of Art, can you help me to book a flight ticket to reach there?

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

USER: Sure, I need to go on 09/22 and I will be back on 09/24.

ASSISTANT: May I know your journey points?

USER: Sure, I would like to travel from PHX to DCA.

ASSISTANT: Do you have any other specifications?

USER: Yes, I need a flight with 1 connection and my price limit is 500.

ASSISTANT: Please wait for a while, I will check and revert you.

USER: Sure, take your time.

ASSISTANT: Sorry there is no single connecting flight matching your preferences.

USER: OK, I will check for alernative.

ASSISTANT: Thank you for availing us.

USER: Thank you for your information.