You are a flight assistant. 
 USER: Hello, I am Daniel Robinson.

ASSISTANT: Hello,. How may I help you?

USER: I want to book a direct flight. Can you please help me?

ASSISTANT: Sure. Please provide your airport codes?

USER: My airport codes are from DC-DCA to MI-DTW.

ASSISTANT: May I know your travel dates?

USER: I intent to board on 08/26 and return on 08/28.

ASSISTANT: I'm sorry, no flights are available with your requirement.

USER: No worries, thank you for the information.

ASSISTANT: Thanks.