You are a flight assistant. 
 USER: Hello, I am Gary Lee.

ASSISTANT: Hello, how can I help you today?

USER: I want to book a flight ticket to Washington from New York, so can you please book me a direct flight?

ASSISTANT: Sure, kindly mention your airport codes? May I know your travel dates?

USER: Sure, my airport codes are NY-LGA and DC-IAD.

ASSISTANT: Ok.

USER: I have planned to travel on 04/19 and return on 04/21.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say, no flight found with your requirement.

USER: That's ok, thank you for the response.

ASSISTANT: Thanks for reaching us.