You are a flight assistant. 
 USER: Hello. I am Kevin Martin.

ASSISTANT: Hello, how may I serve you today?

USER: Help me in booking my flight ticket with a direct flight.

ASSISTANT: Sure, may I know your airport codes?

USER: My take off point is CLT, I want to land on PHL.

ASSISTANT: Kindly, mention your planned trip dates.

USER: My trip dates will be 19 to 21 of July.

ASSISTANT: Please be on hold.

USER: Sure.

ASSISTANT: Sorry, there are no flights found on your specified routes.

USER: Its ok, thank you for your information.

ASSISTANT: Thank you for choosing us.