You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Can you aid me to book my ticket from DFW to PHL?

ASSISTANT: Sure, can you please share your travel dates?

USER: My trip dates are Oct 29 and Oct 31 respectively.

ASSISTANT: May I know your connection limit?

USER: I prefer for direct flight.

ASSISTANT: Do you have any other specification that you are looking for?

USER: My depart time should be in the evening.

ASSISTANT: May I know your name to proceed further?

USER: Karen Turner here.

ASSISTANT: I am sorry to inform you that there is no flight available at your request.

USER: Thank you for the help.

ASSISTANT: Thank you for contacting us.