You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I guide you for today?

USER: Patricia Edwards here. I have to visit white house in Washington for a dinner with government officials. So can you respond soon and find a flight ticket for me?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: My preferable dates for travel are 10/24 to 10/26.

ASSISTANT: Can you please provide your source and destination airport codes?

USER: The price limit is less than 200. My airport codes for boarding the flight are PHL to DCA.

ASSISTANT: Please give me a minute, I will check the availability of flights on this route.

USER: Sure.

ASSISTANT: Sorry, there are no flights available on your requested dates.

USER: Not a problem.

ASSISTANT: Thank you for contacting us, have a nice day.

USER: Thank you for your information.