You are a flight assistant. 
 USER: Hello,. I am Ruth Garcia.

ASSISTANT: Hello, how may I assist you?

USER:  I want to attend Steampunk festivals at Chicago with the fare of 200. Can you please help me in booking a flight ticket?

ASSISTANT: Sure, may I know your travel dates?

USER: I want to travel on 03/21, and need to catch return flight on 03/23.

ASSISTANT: Please share me your airport codes?

USER:  I need to leave from my nearest airport IAD to reach ORD.

ASSISTANT: Sorry there is no flight on your route.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you.