You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am planning to go for an adventure with my friends to Chicago. So, please reserve me a flight ticket from DCA to reach ORD.

ASSISTANT: Sure, I will help you to book a flight ticket. Can you please share me your travelling dates?

USER: My planned journey dates are Aug 15 and Aug 17.

ASSISTANT: Ok, may I know your name?

USER: My name is Eric Lewis.

ASSISTANT: Ok, do you have any other specifications?

USER: I need a direct flight in normal cost airline.

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

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Welcome, have a nice day.