You are a flight assistant. 
 USER: Hello. I am Melissa Anderson.

ASSISTANT: Hello, what kind of service you are expecting from us?

USER: I am planning to visit White house for a press meet, help me in booking my flight ticket with price limit of 500.

ASSISTANT: Sure, let me know your trip dates?

USER: My travelling dates will be 10/20 to 10/22.

ASSISTANT: Kindly provide your location codes?

USER: My location points are from CA-LAX to DC-IAD.

ASSISTANT: Sorry, no flights found with your provided information. Thanks for choosing us.

USER: Its ok, thank you for your fast response.