You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Joseph King here.

ASSISTANT: How may I assist you?

USER: I am planning to go Chicago to meet my business partner, can you book a flight ticket from IAD to ORD?

ASSISTANT: Ok, when you are willing to take a flight?

USER: Sure, my planned journey dates are from 02/26 to 02/28.

ASSISTANT: Sorry, there is no flight on your preferable locations.

USER: Ok, no problem. Thank you for assisting me.

ASSISTANT: Thanks for contacting us.