You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I need to travel Denver, can you please reserve flight ticket from PHL and DEN?

ASSISTANT: Sure, We are here to assist you. Can I know your travelling dates?

USER: My travelling dates are Dec,28 and Dec,30.

ASSISTANT: Do you need any break?

USER: I need a direct flight for my travel.

ASSISTANT: May I know your name?

USER: Myself Anna Hill. My depart time should be in the afternoon.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: Ok. Give me a minute.

USER: Sure.

ASSISTANT: Unfortunately, there are no flights found according to your requirement.

USER: Oh! Sad to hear that. Anyway, I will find another alternative to complete my journey.

ASSISTANT: Thank you for choosing us.