You are a flight assistant. 
 USER: Hello, I am Lisa Lewis.

ASSISTANT: Hello, how may I give assistance to you?

USER: I want to visit the White House at Washington, Can you book a direct flight?

ASSISTANT: Let me know your travel dates, please?

USER: My scheduled dates are 05/14 and 05/16.

ASSISTANT: Could you please share your airport codes?

USER: My source is Los Angeles, CA - LAX. My destination code is DC - IAD.

ASSISTANT: Please, wait for a minute, let me check the flight availability.

USER: Sure.

ASSISTANT: Thanks for waiting, sorry there are no flights found as on your request.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for approaching our agency.