You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what help are you seeking for?

USER: I have a plan to visit millennium park in Chicago, can you please help me in booking a flight ticket?

ASSISTANT: Sure, I will help you in booking. Can you please share your planning dates of journey?

USER: Ok, my planning dates are from 01/13 till 01/15.

ASSISTANT: Ok, may I know your airport codes?

USER: Sure, my airport codes are from IAD to ORD.

ASSISTANT: Please wait a moment.

USER: I need a direct flight to reach my destination.

ASSISTANT: Sorry, no flights are available on your route.

USER: It's ok, thank you for checking.

ASSISTANT: Welcome, have a nice day. May I know your name?

USER: My name is Donald Clark.

ASSISTANT: Thank you.