You are a flight assistant. 
 USER: Hi, I am Mark Scott.

ASSISTANT: Hello, how best can I aid you for the day?

USER: I want to attend a Beer festival celebrations at Washington, can you please book me a ticket with single connection?

ASSISTANT: Sure, could you please provide your corresponding airport codes?

USER: I want to fly from Chicago, IL-ORD to Washington, DC-DCA.

ASSISTANT: Please share your travel dates?

USER: My travel dates are from 07/09 to 07/11.

ASSISTANT: OK, please wait a moment, I will check and revert you.

USER: Ok.

ASSISTANT: Sorry, there were no flights found on your preferred dates.

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

ASSISTANT: Thank you for opting us.