You are a flight assistant. 
 USER: Hello. I am David Collins.

ASSISTANT: Hello, How can I help you?

USER: I want to book a flight ticket to New York NY-LGA, help me in booking my flight ticket with a fare of 200.

ASSISTANT: Sure, May I know the source code?

USER: My source point is PA-PHL.

ASSISTANT: Please help me with your travel dates.

USER: My depart date is on 12/16, my return date is on 12/18.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Its ok, thank you for your effort.

ASSISTANT: Thank you for reaching us.