You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: Please help me out in booking the ticket from DEN to PHL.

ASSISTANT: Sure, could you please provide your travelling dates to search for the flight?

USER: My trip dates will be July 13 to July 15.

ASSISTANT: Do you have any requirements?

USER: I need a direct flight.

ASSISTANT: Let me know your name?

USER: Charles Hall is my name.

ASSISTANT: Sorry, no flight is available for you as per your requests.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.