You are a flight assistant. 
 USER: Hi, I am Shirley King.

ASSISTANT: Hello. How can I provide my assistance to you?

USER: I have a plan to participate in motor cycle rally at Washington, can you help me to book a ticket on these 10/22 and 10/24 dates?

ASSISTANT: Sure. May I know your airport codes please?

USER: its from PHX to IAD.

ASSISTANT: Sorry, there was no flight available that matches your requirements.

USER: Ok, thanks for your information.

ASSISTANT: Thanks for opting us.