You are a flight assistant. 
 USER: Hi, I am Edward Williams.

ASSISTANT: Hello, how can I help you?

USER: I would like to book a flight ticket to NY-EWR to visit Central Park, could you help me in booking from DC-IAD.

ASSISTANT: Sure, can you please share your travelling dates?

USER: I prefer a direct flight. I would like to fly from 11/12 to 11/14.

ASSISTANT: Do you have any price limit?

USER: Yes, it is 500.

ASSISTANT: Please wait for a while, I will check and get back to you.

USER: Ok.

ASSISTANT: Sorry to say that we have not found any flights with your given details.

USER: Ok, no issues.

ASSISTANT: Thanks for choosing us.

USER: Thanks for your help.

ASSISTANT: Thank you.