You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. May I know your good name?

USER: Melissa Miller is my name.

ASSISTANT: How can I help you?

USER: I need to visit Chicago on 02/20 to wish George Washington on his birthday. I need to start from Washington, DC - IAD on 02/19 and return on 02/21. Can you book a flight ticket?

ASSISTANT: Ok, Can you provide the destination airport code?

USER: IL - ORD is my destination airport code.Make sure that price limit should not cross more than 200 with one connection.

ASSISTANT: Ok, wait a while.

USER: Sure.

ASSISTANT: Unfortunately, there is no flights found with your specifications.

USER: Ok, no problem I will check another option. Thanks for your information.

ASSISTANT: Ok, Thank you.