You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER: I am Stephanie Carter, I planned to visit the Seattle to see my sister. Can you help me to find a flight with price of 500?

ASSISTANT: Sure, May I know the travelling dates?

USER: I will depart on 09/09 and return on 09/11.

ASSISTANT: Can you provide your airport codes?

USER: Sure. I will fly from airport IL-ORD and destination is WA-SEA.

ASSISTANT: There is no flights found with your specified dates.

USER: Ok. Thanks for helping me.

ASSISTANT: Thank you.