You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: David Scott here.

ASSISTANT: Scott, how can I assist you?

USER: I need a flight ticket from dates 12/29 to 12/31 for my Charlotte visit. Find the flight with price below 200.

ASSISTANT: Sure, I can help you. Can you please provide me your source and destination airport codes?

USER: My airport codes are LAS to CLT.

ASSISTANT: Ok, please wait for sometime.

USER: Sure.

ASSISTANT: Sorry Scott, there are no flights available on your given dates.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for contacting us and have a nice day.